Quick action is essential during a serious allergic reaction. It helps to remind yourself of action steps so they become second nature if there's an emergency. Here's what to do.

Poor air quality can make asthma worse. Here's what to do about it if you have asthma.

Your eyes itch, your nose is running, you're sneezing, and you're covered in hives. The enemy known as allergies has struck again.

Doctors use several different types of allergy tests, depending on what a person may be allergic to. Find out what to expect from allergy tests.

Asthma is a lung condition that makes it hard to breathe. Learn all about asthma here.

Sports and exercise are a good idea for people with asthma. But some activities are better than others. Find out more.

The weather can affect your asthma symptoms. If you think weather may be triggering your asthma, here are some tips for dealing with it.

People who have celiac disease, a disorder that makes their bodies react to gluten, can't eat certain kinds of foods. Find out more - including what foods are safe and where to find them.

Chronic fatigue syndrome (CFS) is a complicated disease for doctors to diagnose — and even fully understand. Find out more about this often misunderstood condition.

Asthma flare-ups, or attacks, can be handled, but it's even better if you can prevent them. Find out how to deal with flare-ups.

Find out what can make your asthma worse, and what to do about it.

Find out if allergies can make a person's asthma symptoms worse.

Eczema is a common skin problem. Find out more about it and how you can deal with the skin stress.

Living with an egg allergy means you have to be aware of what you're eating and read food labels carefully. Here are some tips for teens who have an egg allergy.

Some people have asthma symptoms only during or after exercise. This is called exercise-induced asthma. Here are some tips for coping with it.

Doctors are diagnosing more and more people with food allergies. Knowing what to expect and how to deal with food allergies can make a big difference in preventing serious illness.

Taking precautions and carrying meds are just part of normal life for someone who has a food allergy. Here are some tips on how to make travel also feel perfectly routine.

With food allergies, preventing a reaction means avoiding that food entirely. But sometimes allergens can be hidden in places you don't expect. Here are tips on living with a food allergy.

Hives cause raised red bumps or welts on the skin. They're pretty common and usually not serious. Find out what to do about hives in this article for teens.

Asthma is more common these days than it used to be. The good news is it's also a lot easier to manage and control.

Lupus is a disease that affects the immune system. Learn how lupus is treated, signs and symptoms, how to support a friend who has it, and more.

Milk is in all kinds of foods, even things like baked goods. So what should a person who's allergic to milk do?

It's very common for teens with asthma to need changes in their medicines, such as a higher dose.

Although food allergies are more common than ever, people who have them may feel different or embarrassed. A good friend can really help.

Find out what the experts have to say.

Peanuts are one of the most common allergy-causing foods, and they often find their way into things you wouldn't imagine. Learn the facts on living with a peanut allergy.

Poison ivy can grow anywhere, from the woods to your backyard. This article for teens has tips on how to avoid the plant and what to do if you get a rash.

PrEP (pre-exposure prophylaxis) is when someone takes medicines every day to lower their risk of getting HIV.

Psoriasis causes skin cells to build up on the surface of the skin where they form itchy, red areas and thick scales. Find out how to deal with psoriasis, and what causes it.

Lots of teens have asthma. Here are tips on keeping it under control so you can prevent (or manage) a flare-up at school.

A person with severe allergies can be at risk for a sudden, serious allergic reaction called anaphylaxis. Luckily, it can be treated.

Shellfish allergies can be serious - and shellfish can appear in some surprising foods and products. Read about shellfish allergy and what to do when a reaction is severe.

Smoking is a bad idea, especially for people with asthma. Here's why.

Watch what it's like to get a spirometry test.

Stem cells can develop into cells with different skills, so they're useful in treating diseases like cancer.

Thrombocytopenia is when someone has too few platelets in their bloodstream. Many things can cause it and most can be treated.

If you have asthma, travel can seem less fun because there's always the worry that something unexpected may cause a flare-up. Here's how to avoid problems so you can concentrate on the fun.

Sometimes people outgrow some food allergies over time, but tree nut allergies are lifelong in many people.

An asthma action plan is a written plan that helps you take control of your asthma. Get the details in this article.

Sickle cell crisis is when sickled cells clog small blood vessels, causing extreme pain and other symptoms. Learn more, including how to help prevent a crisis and what to do if one does happen.

Anemia is when the number of red blood cells in the body gets too low. Red blood cells carry hemoglobin (pronounced: HEE-muh-glow-bin), a protein that carries oxygen throughout the body. Without enough of them, oxygen doesn't get to the body's organs. Without enough oxygen, the organs can't work nor

These videos show what's involved in getting a blood test and what it's like to be the person taking the blood sample.

The genes of both parents are involved for a child to be born with sickle cell disease. Learn all about it.

Crizanlizumab is a medicine that can help people with sickle cell disease. Find out how it works.

A simple blood test can tell you if you have sickle cell trait. Read about it.

Find out how you can support a friend or family member who has sickle cell disease.

Hydroxyurea is a medicine that can help people with sickle cell disease. Find out how it works.

If you have sickle cell trait, find out if it's safe to fly or go to the mountains.

L-glutamine is a medicine that can help people with sickle cell disease. Find out how it works.

Learn about medicines that help people with sickle cell disease stay well and avoid problems before they start.

Sickle cell disease is a blood disorder that makes red blood cells change shape and cause health problems. Find out more in this article for teens.

Find ways to feel good and live a healthy life with sickle cell disease.

Sickle cell trait is a blood condition that gets passed down in families. Even though it doesn’t usually cause health problems, it's important to know if you have it.

People with sickle cell trait can have health problems, but they don’t happen often. Know what to watch for and how to stay well.

Stem cells can develop into cells with different skills, so they're useful in treating diseases like cancer.

Thrombocytopenia is when someone has too few platelets in their bloodstream. Many things can cause it and most can be treated.

At a certain point, you'll no longer be able to see your childhood doctor. Here are tips for teens on making a smooth switch to adult sickle cell care.

When people have Von Willebrand disease, their blood doesn't clot properly. Many teens with VWD have such mild symptoms that they never know they have it.

Voxelotor is a medicine that can help people with sickle cell disease. Find out how it works.

People with sickle cell trait are not as likely to get very sick from malaria as other people. Find out why.

If the tendon just above your heel becomes swollen or irritated due to overuse, it can lead to a painful condition called Achilles tendonitis. Find out how to treat it - and prevent it.

A sprained ankle is a very common injury that happens when the ligaments that support the ankle get overly stretched or torn. Find out how to avoid ankle sprains and what to do if you get one.

ACL injuries can happen in active and athletic kids when excessive pressure is put on the knee joint, resulting in a torn ligament.

Blount disease is a growth disorder that affects the bones of the lower leg. It causes bowing of the leg below the knee, which gets worse if it's not treated.

Bones are tough stuff — but even tough stuff can break. Find out what happens when a bone fractures.

A broken collarbone is one of the most common types of broken bones. Find out how it can happen and how it's treated.

Bursitis, an irritation of the small fluid sacs that provide cushioning in some joints, is often caused by sports-related injuries or repeated use of a particular joint.

This article has tips on taking care of a cast so it keeps working as it should.

Ira has cerebral palsy (CP), but it doesn't interfere with his love of sports or his dream of being a broadcaster. Check out this video.

A comminuted fracture is a type of broken bone. The bone is broken into more than two pieces.

Female athlete triad is a combination of three conditions: disordered eating, amenorrhea (loss of a girl's period), and osteoporosis (a weakening of the bones).

Fibromyalgia is a long-term condition that causes pain in a person's muscles, joints, and other soft tissues. Find out how doctors tell if a person has fibromyalgia and what can be done to treat it.

A broken bone requires emergency medical care. Here's what to do.

A greenstick fracture is a type of broken bone. The bone cracks on one side only, not all the way through the bone.

A groin strain is when one or more of the muscles in the inner thigh gets stretched, injured, or torn. Find out what to do for groin strains.

A hamstring strain happens when one or more of the muscles in the back of the leg gets stretched too far and starts to tear. Find out how to treat hamstring strains in this article for teens.

Most hip pointer injuries can be easily treated and heal in their own time. Find out what to do in this article for teens.

Broken bones have an amazing ability to heal. New bone forms within a few weeks of the injury, although full healing can take longer.

See how the joints work.

Learn about juvenile idiopathic arthritis, a specific kind of arthritis that usually occurs in kids and teens younger than 17.

Caroline loved sports. But when an ongoing knee injury kept her from playing the sports she loved, she discovered new interests. Read her story.

Your spine, or backbone, normally curves forward gently as it runs up your back. Sometimes, though, someone's back can be rounded too far forward, which is a condition known as kyphosis.

Lupus is a disease that affects the immune system. Learn how lupus is treated, signs and symptoms, how to support a friend who has it, and more.

MCL injuries happen when excessive pressure is put on the knee joint, causing a torn ligament.

The key to healing meniscus tears is not to get back into play too quickly. Find out what meniscus tears are and how to treat them.

Osgood-Schlatter disease (OSD) is an overuse injury that can cause knee pain in teens, especially during growth spurts. Learn more.

Sometimes a bad cut that gets infected can lead to even worse things, like a bone infection called osteomyelitis. The easiest way to protect yourself is to practice good hygiene.

Overuse (or repetitive stress) injuries happen when too much stress is placed on a part of the body, causing problems like swelling, pain, muscle strain, and tissue damage.

Patellofemoral pain syndrome (or runner's knee) is the most common overuse injury among runners, but it can also happen to other athletes who do activities that require a lot of knee bending.

In teens, biceps tendonitis is usually an overuse injury that causes tendons in the upper arm to be swollen or irritated. Most cases heal on their own if you follow a few guidelines from your doctor.

Quadriceps contusions are common in sports that have a lot of direct contact or a chance of collisions or wipeouts. Find out what to do if you get one - and how to avoid them.

Repetitive stress injuries (RSIs) happen when movements are repeated over and over, damaging a bone, tendon, or joint.

Scoliosis makes a person’s spine curve from side to side. Large curves can cause health problems like pain or breathing trouble. Health care providers treat scoliosis with back braces or surgery when needed.

Some teens with scoliosis wear a brace to help stop their curve from getting worse as they grow. Find out more about how scoliosis braces work and how long people wear them in this article for teens.

Sever's disease, a common heel injury, is due to inflammation (swelling) of the growth plate in the heel. While painful, it's only temporary and has no long-term effects.

Shin splints are pain on the inner part of the shinbone, often from running or another high-impact activity. They get better with rest.

This growth-related injury is more common in teens who play sports that require a lot of running or jumping. Find out why it happens - and what you can do to avoid and treat it.

A good, stable connection at your hip joint is what lets you walk, run, make that jump shot, and shake it on the dance floor. But in some teens – particularly those who are obese – the hip joint is weakened by slipped capital femoral epiphysis (SCFE).

A spinal fusion is a surgical procedure that's done to stabilize or straighten the bones in the back. It can help some teens with scoliosis.

Steven was diagnosed with SMA when he was 3. Here's a look at his life today and why he says, "When someone tells you you can't do something, don't be afraid to try something new."

A splint is a support device that keeps an injured area from moving. Doctors often use splints to hold bones and joints in place so they can heal after a fracture.

Sprains and strains are common injuries, especially for people who play hard or are into sports. Find out what they are and how to recuperate from one.

It's not always easy to tell if you have a stress fracture, and stress fractures can get worse quickly. This article explains how to prevent and treat them.

Find out what the experts have to say.

If you tore your ACL, you might need this surgery to fix it. Find out what's involved.

You probably can't wait to get back to your normal activities, but it takes a while for a limb that's been in a cast to finish healing. Here's what to expect.

Cerebral palsy is one of the most common developmental disabilities in the United States. It affects a person's ability to move and coordinate body movements.

Ira has cerebral palsy (CP), but it doesn't interfere with his love of sports or his dream of being a broadcaster. Check out this video.

Chronic fatigue syndrome (CFS) is a complicated disease for doctors to diagnose — and even fully understand. Find out more about this often misunderstood condition.

In a concussion, the brain shifts inside the skull. This can cause a sudden — but usually temporary — disruption in a person's ability to function properly and feel well. Here's what to do if you suspect a concussion.

Alex plays high school football, track, basketball, and lacrosse. He's had two concussions. Here, he talks about his experience and what he learned.

It’s important to try to prevent concussions since they can cause long lasting, serious effects on the brain.

Seizures are a common symptom of epilepsy, a condition that affects millions of people worldwide. Learn all about epilepsy, including what to do if you see someone having a seizure.

Fainting is pretty common in teens. The good news is that most of the time it's not a sign of something serious.

A concussion can affect you at school because it's a type of brain injury. Doing schoolwork and being in a classroom can sometimes make things worse. Here's what to know.

Almost everyone gets headaches. So how do you know if a headache is just a passing pain or something more?

Does the thought of Lyme disease make you worry about enjoying the great outdoors? Here's some information to help you lower your risk for Lyme disease.

Lyme disease can be treated if it's caught early. Find out what causes it, how it's treated, and how to prevent it.

If you've ever had a migraine, you know that these headaches can cause severe pain and other symptoms. Read about migraine causes, treatments, prevention tips, and lots more.

Strokes are more common in older adults, but teens can have one too. This "brain attack" happens when blood flow to the brain stops, even for a second.

A tic is a sudden, repetitive movement or sound that some people make, which can be difficult to control.

Tourette syndrome affects the body's brain and nervous system by causing tics - repeated, uncontrollable movements or involuntary vocal sounds.

While many head injuries are mild and don’t cause any problems, some injuries are more serious and can lead to a concussion. Here's what to do if you have a head injury.

As long as people play sports, there will be concussions from time to time. Find out how to protect yourself and when it's safe to return to sports after a concussion.

There's no one reason why people get depressed - many different things can play a role. Find out more about the things that can trigger depression.

Helmets are a way to help protect your head from injuries like cuts and skull fractures.

When chemotherapy and other treatments attack cancer cells, they can affect some of the body's healthy cells too. As a teen, you'll want to know what this can mean to your fertility.

Get the basics on cancer and cancer treatments in this article.

Chemotherapy (chemo) is treatment with medicines that stop the growth of cancer cells. Find out how chemo works and what to expect when getting treatment.

It's unusual for teens to have cancer, but it can happen. The good news is that most will survive and return to their everyday lives. Learn about how to cope if you or someone you know has cancer.

Melanoma is different from other skin cancers because it can spread if it's not caught early. Find out how to lower your risk of getting melanoma and how doctors treat it.

It's hard to know how to respond when someone you love — someone your own age — is diagnosed with cancer. Here are some thoughts on dealing with feelings and helping your friend.

Many people with cancer are treated with radiation therapy. Get the facts on radiation therapy, including what it is, what to expect, and how to cope with side effects.

Side effects of cancer treatment can include flu-like symptoms, hair loss, and blood clotting problems. After treatment ends, most side effects go away.

Stem cells can develop into cells with different skills, so they're useful in treating diseases like cancer.

If your doctor prescribed steroids as part of your treatment for an illness, don't worry. It's not the illegal, doping scandal kind of steroid. Get the details in this article for teens.

Thrombocytopenia is when someone has too few platelets in their bloodstream. Many things can cause it and most can be treated.

People who have celiac disease, a disorder that makes their bodies react to gluten, can't eat certain kinds of foods. Find out more - including what foods are safe and where to find them.

Cholera is an intestinal infection that mostly affects people in tropical regions. Find out more about cholera in this article for teens.

Constipation is a very common problem that usually happens because a person's diet doesn't include enough fluids and fiber. In most cases, making simple changes can help you feel better.

Crohn's disease is a condition that causes parts of the intestine (bowel) to get red and swollen. It can be challenging to deal with, but many teens find that they're able to feel well and have few symptoms for long periods of time.

Cystic fibrosis (CF) is an inherited disease that causes the body to produce mucus that's extremely thick and sticky. It mainly affects the lungs and the pancreas, causing serious breathing and digestive problems.

Besides extra calories, teens with cystic fibrosis have some specific nutritional needs. Find out more.

This sample meal plan for teens with cystic fibrosis provides a day's worth of meals that add up to about 3,750 calories.

Gastroesophageal reflux disease doesn't just affect old people who eat too much while watching TV. Active, healthy teens can have GERD too.

A hernia is an opening or weakness in the wall of a muscle, tissue, or membrane that normally holds an organ in place. Learning to prevent hernias isn't hard to do - check out these tips.

Indigestion is just another name for an upset stomach. It usually happens when people eat too much or too fast, or have foods that don't agree with them.

Inflammatory bowel disease is an ongoing illness caused by an inflammation of the intestines. There are two kinds of IBD: Crohn's disease and ulcerative colitis.

Some teens get stomachaches and diarrhea often. Read about irritable bowel syndrome (IBS), a common intestinal disorder that affects the colon.

If you have lactose intolerance, you're not alone. Lots of people have the condition. Check out these tips on dealing with lactose intolerance.

Lots of different problems can cause similar kinds of stomach pain - not all of them related to the digestive system. Here are some clues about what could be going on.

Ulcerative colitis is a type of inflammatory bowel disease (IBD) that happens only in the colon. It causes the inner lining of the colon to get red and swollen with sores called ulcers.

Peptic ulcers are common, but mostly affect adults. Most can be cured.

See what it's like to get an upper GI test.

Sickle cell crisis is when sickled cells clog small blood vessels, causing extreme pain and other symptoms. Learn more, including how to help prevent a crisis and what to do if one does happen.

Humans, animals, and even plants can have albinism, a condition that gives people a kind of pale appearance. Find out more about albinism here.

The genes of both parents are involved for a child to be born with sickle cell disease. Learn all about it.

A dwarf is a short-statured person whose adult height is 4 feet 10 inches or under. Find out what happens when a person has dwarfism and why some people are born with it.

Emily was adopted from Russia, where she was born with a type of dwarfism. In this video, she talks about her life philosophy and how she overcame the many hurdles she faced.

Genes play an important role in how we look and act, and even in whether we get sick. This article gives the lowdown on genes, genetic disorders, and new research into gene therapy.

A simple blood test can tell you if you have sickle cell trait. Read about it.

Hydroxyurea is a medicine that can help people with sickle cell disease. Find out how it works.

This genetic condition only affects guys and is also called "XXY." It can affect a guy's ability to learn and his sexual development, but doctors can treat it. Find out more.

L-glutamine is a medicine that can help people with sickle cell disease. Find out how it works.

Metabolic syndrome is a signal that someone could be on the road to serious health problems. Find out more in this article for teens.

Find ways to feel good and live a healthy life with sickle cell disease.

Sickle cell trait is a blood condition that gets passed down in families. Even though it doesn’t usually cause health problems, it's important to know if you have it.

Turner syndrome is a genetic disorder that affects about 1 in every 2,500 girls. Learn more about the condition and how doctors treat it.

When people have Von Willebrand disease, their blood doesn't clot properly. Many teens with VWD have such mild symptoms that they never know they have it.

Voxelotor is a medicine that can help people with sickle cell disease. Find out how it works.

Lots of people wonder if they have hypoglycemia, but the condition is not common in teens. Get the facts on hypoglycemia.

People with sickle cell trait are not as likely to get very sick from malaria as other people. Find out why.

The things you do now could help prevent diabetes later, depending on the type of diabetes. Here's the scoop on diabetes prevention.

Chronic fatigue syndrome (CFS) is a complicated disease for doctors to diagnose — and even fully understand. Find out more about this often misunderstood condition.

People with diabetes don't need to be on strict diets, but do need to pay attention to what they eat and when. Crack open the cookbooks and surf to your favorite recipe website because it's time to plan meals that you love!

Taking care of your diabetes includes knowing when to call a doctor and get medical help.

A dwarf is a short-statured person whose adult height is 4 feet 10 inches or under. Find out what happens when a person has dwarfism and why some people are born with it.

In most cases, teens who are small are just physically maturing a bit more slowly than their friends. Occasionally, though, there's a medical reason why some kids and teens stop growing. Find out about growth problems and how doctors can help.

Being sick is no fun for anyone. For people with diabetes, being sick can also affect blood sugar levels.

People who have diabetes may hear or read a lot about controlling, or managing, the condition. But what is diabetes control and why is it so important?

You probably spend more than a third of your waking hours at school. Chances are you'll need to check your blood sugar levels or give yourself an insulin injection during that time. So what do you do?

Diabetes medicines help keep blood sugar levels in a healthy range and may help prevent problems now and later.

Teens with diabetes can exercise and play sports at the same level as everyone else, so whether you want to go for the gold or just go hiking in your hometown, diabetes shouldn't hold you back.

If you're an athlete, find out how to keep doing your favorite sport while keeping your diabetes under control.

People with type 1 diabetes need to follow a treatment plan to manage their diabetes and stay healthy and active.

People with type 2 diabetes need to follow a plan to manage their diabetes and stay healthy and active.

Diabetes affects how the body uses glucose, a sugar that is the body's main source of fuel. In type 1 diabetes, glucose can't get into the body's cells where it's needed.

Teens with type 2 diabetes have to pay close attention to what they eat and do.

It takes all of your team members — you, your parents, doctors, dietitians, and mental health pros — to help you take care of your diabetes.

Arrhythmias are abnormal heartbeats usually caused by an electrical "short circuit" in the heart. Many are minor and not a significant health threat, but others can indicate a more serious problem.

Atrial septal defect, or ASD, is a heart defect that some people are born with. Most ASDs are diagnosed and treated successfully with few or no complications.

When someone has coarctation of the aorta, that person's aorta (the major blood vessel that carries blood away from the heart to the body) is narrowed at some point.

An echocardiogram (also called an echo or cardiac ultrasound) uses sound waves to create pictures of the heart. See why doctors might order this test for teens.

This video shows what it's like to have an electrocardiogram (EKG for short).

High blood pressure, also called hypertension, is more common in adults, but it can happen at any age. Learn what it is and how to treat it.

Ventricular septal defect, or VSD, is a heart condition that a few teens can have. Find out what it is, how it happens, and what doctors do to correct it.

Bedwetting can be embarrassing and upsetting for teens, but there are effective ways to correct the problem and scientists are constantly developing new treatments.

Hematuria is pretty common, and most of the time it's not serious. Find out what causes blood in the urine and what to do about it.

Dialysis is a medical treatment that can take over the job of filtering the blood until a person's failing kidneys heal or are replaced with a kidney transplant. Find out more in this article for teens.

With glomerulonephritis, tiny filtering units in the kidneys stop working properly, causing problems like too much fluid in the body and swelling. Most of the time it can be treated. Find out more.

Hemodialysis is the type of kidney dialysis that doctors use most to take over the kidneys' job of filtering the blood. Find out more in this article for teens.

Sometimes, the kidneys can't do their job properly. In teens, kidney disease is usually due to infections, structural issues, glomerulonephritis, or nephrotic syndrome.

Kidney stones mostly happen to adults, but sometimes teens can get them. Find out what kidney stones are, how to treat them, and ways to help prevent them.

If the kidneys stop working, a person will need either dialysis or a transplant. Get the facts on kidney transplant in this article for teens.

This medical treatment helps people with kidney failure. It can be done at home, often overnight, to take over the kidneys' job of filtering blood. Find out more in this article for teens.

A urinary tract infection (UTI) is one of the most common reasons that teens visit a doctor. Learn about the symptoms of UTIs, how they're treated, and more in this article.

ADHD is a medical condition caused by brain differences that affect attention and behavior in specific ways. This article for teens has the basics on ADHD.

Medicine doesn’t cure ADHD. But it does help boost a person's ability to pay attention, slow down, and have more self-control. This article for teens has details on how ADHD medicines help.

It takes time to learn to manage ADHD. These tips for teens can help with school and learning.

Autism spectrum disorder can make communicating and interacting with other people difficult. Find out more.

Therapy is part of the treatment for ADHD. This article is for teens who want to know what to expect from therapy and how it works for ADHD.

Dyslexia is a learning disability in which people have difficulty learning to read, even though they are smart enough and are motivated to learn. Learn more about dyslexia and how to deal with it.

Asthma is a lung condition that makes it hard to breathe. Learn all about asthma here.

Cystic fibrosis (CF) is an inherited disease that causes the body to produce mucus that's extremely thick and sticky. It mainly affects the lungs and the pancreas, causing serious breathing and digestive problems.

Besides extra calories, teens with cystic fibrosis have some specific nutritional needs. Find out more.

Teens with cystic fibrosis have some specific nutritional needs. Here's how they can meet those needs.

An incentive spirometer is a way to do breathing exercises to help with healing after surgery or to manage an illness. See how to use one.

If you have sickle cell trait, find out if it's safe to fly or go to the mountains.

An incentive spirometer is a way to do breathing exercises to help with healing after surgery or to manage an illness. This article explains how incentive spirometry works.

Watch what it's like to get an X-ray.

If you're afraid of shots, you're not alone. Next time your doc asks you to roll up your sleeve, try these tips.

These videos show what's involved in getting a blood test and what it's like to be the person taking the blood sample.

A magnesium test looks at levels of the mineral magnesium in a person's blood. Find out why doctors do this test and what's involved.

A phosphorus test looks at levels of phosphorus in a person's blood. Find out why doctors do this test and what's involved for teens.

See what it's like to get a CAT scan.

An echocardiogram (also called an echo or cardiac ultrasound) uses sound waves to create pictures of the heart. See why doctors might order this test for teens.

This video shows what it's like to have an electrocardiogram (EKG for short).

This video shows what it's like to get an IV.

During a blood draw, some people might have a vasovagal reaction. Learn more.

This video shows what it's like to get an MRI.

A spinal fusion is a surgical procedure that's done to stabilize or straighten the bones in the back. It can help some teens with scoliosis.

Watch what it's like to get a spirometry test.

Stem cells can develop into cells with different skills, so they're useful in treating diseases like cancer.

This video shows what it's like to get a strep test.

See what it's like to get an upper GI test.

This video shows what it's like to get a urine test.

Watch what it's like to get an X-ray.

Canker sores are fairly common, and they usually go away on their own without treatment. Read this article for teens to find out more, including tips on what to do about the pain.

Gum disease doesn't just happen to people your grandparents' age - it can happen to teens too. Get the details here.

A peritonsillar abscess is an area of pus-filled tissue at the back of the mouth, next to one of the tonsils. Find out how it happens and what to do.

Find out what the experts have to say.

Bad breath, or halitosis, can be a major problem, especially when you're about to snuggle with your sweetie or whisper a joke to your friend. The good news is that bad breath often can be easily prevented.

Here are 5 practical tips on goal setting that can help make it easier to set and reach goals.

We use the words "oveweight" and "obese" a lot, but they actually have medical meanings. Find out how doctors diagnose these conditions and what they mean for a person's health.

Acanthosis nigricans is a darkening and thickening of the skin that can be a sign of other medical conditions. Find out more.

One of the biggest questions guys and girls have as they grow and develop is whether they're the right weight. One place to start is by learning about body mass index, or BMI.

Cholesterol is a type of fat found in your blood. The body needs some cholesterol, but too much can be a problem. Discover more about cholesterol.

If a person is struggling with extra weight, it can add to the emotional ups and downs of being a teen. Get some tips on coping here.

We've all eaten a whole bag of chips out of boredom or while cramming for a big test. Learn more about emotional eating, and how to manage it, in this article for teens.

Keeping an exercise log is a great way to stay motivated and reach exercise goals.

There are several different types of weight loss surgeries. One type is gastric sleeve surgery, also known as sleeve gastrectomy. Find out what's involved and who gets it in this article for teens.

Lots of people are unhappy with their present weight, but aren't sure how to change it - or even if they need to. Get the facts on weight loss here.

High blood pressure, also called hypertension, is more common in adults, but it can happen at any age. Learn what it is and how to treat it.

Brandon, 17, has lost 70 pounds through better eating and exercise. In this video he talks about what inspired him and how he stayed on track.

Metabolic syndrome is a signal that someone could be on the road to serious health problems. Find out more in this article for teens.

In polycystic ovary syndrome (PCOS), the ovaries produce higher than normal amounts of certain hormones, which can interfere with egg development and release. Learn how doctors diagnose and treat PCOS.

Losing weight can feel like a challenge, no matter how much we want it. It can sometimes seem like our minds are working against us. That's where weight-management counselors can help.

Weight loss surgery works. But it's serious stuff, both physically and emotionally. Find out about two weight loss surgery options for teens.

These videos guide teens through basic strength training exercises. Anyone can do these exercises, and they work well as part of a weight-loss plan.

If you're overeating often, here are some things that might help

A couple of pounds of extra body fat are not a health risk for most people. But when people are severely overweight, it can cause health problems.

Getting the right amount of exercise can rev up your energy levels and even help you to feel better emotionally. Find out why.

Alex plays high school football, track, basketball, and lacrosse. He's had two concussions. Here, he talks about his experience and what he learned.

Emily was adopted from Russia, where she was born with a type of dwarfism. In this video, she talks about her life philosophy and how she overcame the many hurdles she faced.

Caroline loved sports. But when an ongoing knee injury kept her from playing the sports she loved, she discovered new interests. Read her story.

Steven was diagnosed with SMA when he was 3. Here's a look at his life today and why he says, "When someone tells you you can't do something, don't be afraid to try something new."

If periods aren't regular it's usually because a girl's body is still developing. But sometimes, changes in blood flow can be a sign of abnormal uterine bleeding (AUB).

It's rare for teen girls to have breast problems. But sometimes a doctor or nurse might think a breast exam is a good idea. Find out why, as well as what's involved in a breast exam.

Getting the HVP vaccine is still a good idea because there are different types of HPV.

Concerned about your growth or development? Puberty can be delayed for several reasons. Luckily, doctors usually can help teens with delayed puberty to develop more normally.

Endometriosis is when tissue that looks and acts like the lining of the uterus grows outside the uterus. Here's how doctors help people who have it.

Female athlete triad is a combination of three conditions: disordered eating, amenorrhea (loss of a girl's period), and osteoporosis (a weakening of the bones).

A hernia is an opening or weakness in the wall of a muscle, tissue, or membrane that normally holds an organ in place. Learning to prevent hernias isn't hard to do - check out these tips.

AIDS can happen after someone has had HIV for many years and isn’t treated. But not all people with HIV will develop AIDS. Learn how HIV spreads.

Wondering whether it's normal to have irregular periods? Get the facts about this common problem.

Vaginal discharge keeps the vagina clean and moist, and helps prevent and fight infections. Some changes are normal but others may mean there’s a problem.

This genetic condition only affects guys and is also called "XXY." It can affect a guy's ability to learn and his sexual development, but doctors can treat it. Find out more.

A pelvic exam is where a doctor or nurse practitioner looks at a girl's reproductive organs (both outside and internally) and feels the uterus and ovaries to be sure everything's normal. Find out what's involved in this article for teens.

Get the facts on which period problems are normal and which ones might indicate something's going on.

In polycystic ovary syndrome (PCOS), the ovaries produce higher than normal amounts of certain hormones, which can interfere with egg development and release. Learn how doctors diagnose and treat PCOS.

Serious testicular injuries are relatively uncommon, but testicular injury can be painful. Here's how you can protect yourself from injury.

This emergency condition happens when the spermatic cord gets twisted and cuts off blood supply, causing pain and swelling. Find out what to do in this article for teens.

Turner syndrome is a genetic disorder that affects about 1 in every 2,500 girls. Learn more about the condition and how doctors treat it.

A varicocele is an enlargement of the veins in the scrotum. Although there is no way to prevent a varicocele, it usually needs no special treatment.

Find out what the experts have to say.

Earbuds are basically a tiny pair of speakers that go inside the ears. They're fine at low volumes, but they can cause permanent hearing loss if not used properly. Find out what's safe (and not) in this article for teens.

Perforated eardrums can really hurt. And if you can't hear as well as usual, they can be scary. The good news is, most people who have them get all their hearing back eventually.

Want to hear what's being said to you, by you, and about you? Find out how hearing aids help people with certain types of hearing loss.

Hearing loss (also called hearing impairment) makes it hard to hear or understand sounds. But you can do something about noise-induced hearing loss.

Do you know someone who stutters or has another speech disorder? Find out how speech disorders are treated, how you can help a friend or classmate cope, and lots more.

A stye is a backed-up oil gland in the eyelid. Styes are usually easy to get rid of, but there are some things you can do to help. Learn more about styes.

When one or more parts of the eye or brain that are needed to process images become diseased or damaged, severe or total loss of vision can occur. Read all about visual impairment.

Acanthosis nigricans is a darkening and thickening of the skin that can be a sign of other medical conditions. Find out more.

Almost every teen gets acne at some point. This article addresses common questions and concerns about acne and tells you what you can do about it.

Although the name athlete's foot sounds funny, if you have this skin infection, you're probably not laughing. The good news is that it is generally easy to treat.

Blisters, calluses, and corns can be uncomfortable, but they're also pretty common and easy to prevent. Find out what to do in this article for teens.

Learn about bruises, why they happen, how to make them go away faster, and why they turn all those funny colors.

Scars from acne can seem like double punishment - first you had to suffer through the pimples, now you have marks to remind you. Is there anything you can do?

Cellulite is the lumpy look ("cottage cheese") commonly found on the thighs, stomach, and butt. It's due to collections of fat that push against the connective tissue beneath the skin.

Most small cuts, scrapes, or abrasions heal on their own. Here are tips for teens on how to treat cuts at home - and when to get medical help.

If you're worried about dandruff, you're not alone. Dandruff can start in puberty, and lots of teens and adults live with it. Learn how to control it.

Lice aren't dangerous, but they do spread from person to person easily. They can also be hard to get rid of. Find out how to prevent lice -- and what to do if someone you know has them.

Hives cause raised red bumps or welts on the skin. They're pretty common and usually not serious. Find out what to do about hives in this article for teens.

Find out what the experts have to say.

A toenail is ingrown when it begins to break through and grow into the soft skin of the toe. Find out more about ingrown toenails.

Jock itch is a pretty common fungal infection of the groin and upper thighs. It is generally easy to treat - and avoid - by following a few simple steps.

Keratosis pilaris is a common skin condition that causes tiny bumps, often on the upper arms, thighs, buttocks, or cheeks. Learn the symptoms and treatments.

Lupus is a disease that affects the immune system. Learn how lupus is treated, signs and symptoms, how to support a friend who has it, and more.

The skin rash molluscum contagiosum isn't a big deal. Find out what to do about it in this article for teens.

Pityriasis rosea is a pink or gray skin rash that's common in teens and young adults. It may itch, but it's harmless. Find out what to do about it in this article for teens.

Psoriasis causes skin cells to build up on the surface of the skin where they form itchy, red areas and thick scales. Find out how to deal with psoriasis, and what causes it.

Ringworm isn't a worm at all - it's the name for a type of fungal skin infection. The good news is that ringworm is easy to treat.

People can get abscesses on the skin, under the skin, in a tooth, or even inside the body. Most abscesses are caused by infection, so it can help to know what to do. Find out in this article for teens.

Vitiligo is a loss of skin pigment that causes white spots or patches to appear on the skin. It's not medically dangerous, but it can affect a person's appearance. Find out more.

There's no sure way to prevent acne. But these tips might help reduce the number and severity of your breakouts.

How well a wound heals depends on where it is on the body and what caused it – as well as how well someone cares for the wound at home. Find out what to do in this article for teens.