The kidneys play a critical role in the body: Acting as the body's filtering system, they help control water levels and eliminate wastes through urine (pee). They also help regulate blood pressure, red blood cell production, and the levels of calcium and minerals.
But sometimes the kidneys don't develop properly and, as a result, don't function as they should. Often these problems are genetic and not due to anything a parent did or didn't do.
Many of these problems can be diagnosed before a baby is born through routine prenatal testing and treated with medication or surgery while the child is still young. Other problems may appear later, with symptoms such as urinary tract infections (UTIs), growth problems, or high blood pressure (hypertension).
In some cases, the problems can be severe and require surgical treatment.
The kidneys are like the body's garbage collection and disposal system. Through microscopic units called nephrons, the kidneys remove waste products and extra water from the food a person eats, returning chemicals the body needs (such as sodium, phosphorus, and potassium) back into the bloodstream. The extra water combines with other waste to become urine, which flows through thin tubes called ureters to the bladder, where it stays until it exits through the urethra (the tube that carries urine out of the body from the bladder) when someone goes to the bathroom.
The kidneys also produce three important hormones:
Kidney failure, which is also called renal failure, is when the kidneys slow down or stop properly filtering wastes from the body, which can cause buildups of waste products and toxic substances in the blood. Kidney failure can be acute (sudden) or chronic (happening over time and usually long lasting or permanent).
Acute kidney injury (sometimes called acute kidney failure) may be due to bacterial infection, injury, shock, heart failure, poisoning, or drug overdose. Treatment includes correcting the problem that led to the kidney injury and, in some cases, dialysis .
The most common kidney diseases in children are present at birth. They include:
Congenital problems with the urinary tract: As a baby develops in the womb, part of the urinary tract can grow to an abnormal size or in an abnormal shape or position. These problems include:
Sometimes a child can have other health problems that affect how well the kidneys function. These can include:
The signs and symptoms of urinary tract or kidney problems vary and include:
If a kidney disease is suspected, the doctor will take a medical history, do a physical exam, and order urine tests, blood tests, imaging studies, or a biopsy to help make a diagnosis. These studies are usually suggested by a nephrologist, a doctor who specializes in the diagnosis and treatment of kidney diseases.
With urinalysis (a type of urine test), the doctor can quickly detect abnormalities (such as too many red blood cells) that may signal inflammation or irritation in the urinary tract. Urinalysis can also detect an of excess white blood cells, which is most commonly associated with bladder and kidney infections.
Certain blood tests tell doctors how well the kidneys are filtering waste products and balancing the bloodstream's chemical makeup.
Two other important diagnostic tools doctors use are blood pressure and growth measurements. Along with the heart, the kidneys are crucial to determining blood pressure. High blood pressure in a child is an important sign that the kidneys need to be evaluated. Accurate growth measurements can provide a clue to diagnosing some kidney diseases because kids with chronic kidney disease often have growth problems.
The doctor may use a kidney biopsy to evaluate kidney function. A biopsy is a procedure in which a small piece of the kidney tissue is removed with a needle. Performed while a child is under anesthesia, it's a simple procedure that can help make an accurate diagnosis of the kidney problem in about 9 out of 10 cases. It's especially helpful in the diagnosis of nephritis and nephrosis.
In addition to standard X-rays, other imaging studies a doctor may use to help diagnose kidney diseases include:
Reviewed by: KidsHealth Medical Experts