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Kids' Medical Dictionary

  • What Are Immunizations?

    This is the long word for what most kids know as vaccines.

  • What Are Infections?

    When germs get inside your body, they can multiply and cause an infection.

  • What Are Insulin Injections?

    Insulin is an important hormone that keeps the body working. If the body doesn't make enough of this substance, a person may need to get insulin injections.

  • What Are Involuntary Muscles?

    You don't have any say over what this kind of muscle does and when.

  • What Are Islet Cells?

    The pancreas contains clusters of cells that make hormones. These clusters are known as islets.

  • What Does Inhale Mean?

    You're doing it now . . . and now . . . and now . . . and now!

  • What Is Ibuprofen?

    Ibuprofen is a kind of pain reliever that helps ease aches and pains.

  • What's an Ileus?

    An ileus is when the intestines stop working and don't move food, fluid, and gas the way they are supposed to.

  • What's an Inhaler?

    An inhaler is a plastic tube that holds a container of medicine that comes out in a spray and is breathed into the lungs.

  • What's an Injection?

    An injection is when the doctor uses a needle to put medicine or a vaccine into your body.

  • What's an Insulin Pump?

    A person needs the hormone insulin so the body can function properly. If the body doesn't make enough insulin, one way to get it is through an insulin pump.

  • What's an IV Line?

    IV is short for intravenous.

  • What's Immunotherapy (Allergy Shots)?

    Imagine if you were always sneezing because you were allergic to something.

  • What's Influenza?

    Influenza is a longer word for the flu.

  • What's Insulin Resistance?

    Even though the pancreas is still making insulin, the body doesn't let insulin do its job as well and it's harder for glucose to get into the cells. This is called insulin resistance.

  • What's Insulin?

    If someone has diabetes, they have trouble with a hormone called insulin.

  • What's Irritable Bowel Syndrome?

    Irritable bowel syndrome happens when the muscles in the large intestine have trouble doing their job.

  • What's the ICU?

    Short for intensive care unit, this is a place in the hospital where people can recover from very serious illnesses, accidents, or operations.

  • What's the Immune System?

    This body system, which includes white blood cells and lymph nodes, helps protect your body from disease.

  • What's the Intensive Care Unit (ICU)?

    The intensive care unit, or ICU, is a special place in the hospital where people can recover from very serious illnesses, accidents, or operations.

  • What's the Iris?

    Your iris is the colored part of your eye. So if someone has brown eyes, it means that person's irises are brown.

  • Word! Impetigo

    Impetigo is a skin infection that can happen when bacteria get inside your skin from a cut.

  • What Are Migraines?

    A migraine is a really bad kind of headache that can make you feel dizzy or even sick to your stomach.

  • What Does Menstruation Mean?

    Menstruation is a period — the 2 to 7 days each month that a girl or woman experiences menstrual flow.

  • What Does Myopia Mean?

    Myopia is also known as nearsightededness, which means you can see things up close, but have trouble seeing objects far away, like the words on a chalkboard.

  • What Is Malocclusion?

    Malocclusion is a word that dentists and orthodontists use when your teeth don't come together like they should.

  • What Is Meningitis?

    The meninges cover and protect the brain and spinal cord. Meningitis happens when the meninges swell or get irritated.

  • What Is Multiple Sclerosis?

    When someone has multiple sclerosis, their nerves don't send signals to the brain the way they should.

  • What's a Microscope?

    A microscope is a very powerful magnifying glass.

  • What's a Mucous Membrane?

    Just as skin lines and protects the outside of the body, mucous membranes line and protect the inside of your body.

  • What's an MRI?

    MRI machines take detailed pictures of the insides of people's bodies to help doctors learn what's wrong when there's a problem.

  • What's Melanin?

    Ever wonder where your skin gets its color?

  • What's Mononucleosis?

    People call mononucleosis "kissing disease" because you can get it from someone else's saliva. Mono can make you feel super tired and sick.

  • What's Mucus?

    When you think of mucus, you might think of snot, which is that sticky stuff inside your nose.

  • What's Myalgia?

    Myalgia is muscle pain — when muscles hurt because of an injury, overuse, or a medical condition.

  • What Are Red Blood Cells?

    Red blood cells have the important job of carrying oxygen.

  • What Are Retractions?

    Retractions are a sign someone is working hard to breathe.

  • What Does REM Stand for?

    This is short for rapid eye movement, the stage of sleep when your eyes move back and forth under your closed eyelids and you have dreams.

  • What Does Rx Mean?

    This is short for the word prescription.

  • What Is Retinopathy?

    Retinopathy is the medical word for disease of the retina.

  • What Is Roseola?

    Roseola is a sickness that mostly affects babies and toddlers. It can cause a high fever and a rash on the belly or chest.

  • What Is Rotavirus?

    Rotavirus is a virus that affects the digestive system. It can make people throw up a lot or have bad diarrhea.

  • What's a Radiologist?

    When a kid gets an X-ray or a CT scan (two types of pictures taken of the inside of the body), those funny-looking pictures can be tough to understand.

  • What's a Rash?

    A rash is when skin gets irritated — red, bumpy, scaly, blistered, or itchy. Lots of things can cause rashes.

  • What's a Retainer?

    Your teeth won't go far, but they can move after your braces are removed.

  • What's a Rheumatologist?

    This special doctor deals with rheumatological problems (conditions that involve swelling and pain in muscles and joints).

  • What's a Rhinovirus?

    No, this isn't a rhinoceros with the sniffles.

  • What's Respiratory Syncytial Virus (RSV)?

    Respiratory syncytial virus, or RSV, is an infection of the lungs and breathing passages.

  • What's Rhinitis?

    Rhinitis is irritation and swelling of the lining of the nose - also known as a runny nose.

  • What's Ringworm?

    Ringworm isn't a worm at all. It's an infection on the skin or nails caused by a fungus.

  • What's the Retina?

    The retina is at the back of your eye and it has light-sensitive cells called rods and cones.

  • What Are Sebaceous Glands?

    Sebaceous glands make oil to keep skin soft and smooth.

  • What Are Semicircular Canals?

    Your semicircular canals are three tiny, fluid-filled tubes in your inner ear that help you keep your balance.

  • What Are Sulfites?

    Sulfites are food preservatives that can cause breathing problems in some people with asthma.

  • What Are Symptoms?

    When you're sick, you usually have symptoms — body changes like a fever that let you know something's not right.

  • What Does Sphenopalatine Ganglioneuralgia Mean?

    This is another name for an ice cream headache.

  • What Does Stat Mean?

    Quick! On the double! Hurry up! Get moving!

  • What Does Sternutation Mean?

    This is a long word for something that happens in a short time: sneezing!

  • What Is Scoliosis?

    Scoliosis is an abnormal curve of the spine, also known as the backbone.

  • What Is Sebum?

    You can't see it, but it's there. Sebum is your skin's natural oil, and it keeps your skin soft and makes it a bit waterproof.

  • What Is Surgery?

    Surgery, also called an operation, is when doctors fix something inside the body to make the person feel better.

  • What's a Scab?

    When you get a cut or scrape your blood forms a clot to stop the bleeding. When the clot dries and hardens it's called a scab.

  • What's a Scar?

    A scar is a mark left on your skin from a cut or wound that has healed.

  • What's a Seizure?

    You might hear a seizure called a convulsion, fit, or spell.

  • What's a Skin Test?

    If you might have allergies, a special doctor called an allergist can help figure out what you are allergic to by giving you a skin test.

  • What's a Spacer?

    A spacer makes it easier to use an inhaler.

  • What's a Spinal Tap?

    A spinal tap is an important test for diagnosing illnesses, such as meningitis.

  • What's a Spirometer?

    A spirometer is an instrument that measures how well your lungs are working.

  • What's a Sprain?

    A sprain happens when the ligaments in one of your joints gets stretched too far or torn.

  • What's a Stethoscope?

    When you go to the doctor, they probably use something called a stethoscope to hear the sounds that the inside of your body makes.

  • What's a Strain?

    A strain happens when a muscle gets stretched too far.

  • What's a Strep Screen?

    If you've ever gone to the doctor with a really sore throat, you may have had a strep screen.

  • What's a Stye?

    A stye is a small bump near the edge of the eyelid where the eyelashes are.

  • What's a Suture?

    This is the string that doctors use to sew things together.

  • What's a Syringe?

    A syringe is the needle a doctor uses to give you a shot or draw blood.

  • What's Saliva?

    Saliva is none other than spit, the clear liquid in your mouth that's made of water and other chemicals.

  • What's Scabies?

    Scabies is an itchy skin problem caused by teeny mites that dig tunnels underneath the skin's surface.

  • What's Scarlet Fever?

    Scarlet fever is an infection caused by the same bacteria that cause strep throat. It's called scarlet fever because it causes a red, bumpy rash over most of the body.

  • What's Shingles?

    Shingles is the same virus as the one that gives people chickenpox. It can cause sores or blisters on the body and is very painful.

  • What's Sinusitis?

    Sinusitis is an infection of your sinuses — the air-filled spaces found in the bones of the face around the nose.

  • What's Snot?

    Snot, or mucus, is that sticky, slimy stuff inside your nose.

  • What's Strep Throat?

    Strep throat is an infection caused by bacteria.

  • What's the Sclera?

    The sclera is the white part of your eye.

  • What's the Stapes?

    The stapes is the body's smallest bone!

  • What's a Yawn?

    Yawning is when you stretch your mouth open wide.

  • What's a Yeast Infection?

    A yeast infection is a skin infection caused by a fungus called candida. It can cause white spots in the mouth or an itchy, red rash.

  • What's Yellow Fever?

    Yellow fever is a disease caused by a virus carried by mosquitoes. It's called yellow fever because it can cause jaundice, which turns the skin yellow.

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