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Health Information For Parents
May also be called: Unilateral Hydronephrosis; Bilateral Hydronephrosis; Urinary Obstruction; Swollen Kidneys
Hydronephrosis (hi-dro-ne-FRO-sis) is when one or both kidneys become enlarged because the flow of urine (pee) is backed up or blocked.
Normally, urine flows from the kidneys to the bladder through thin tubes called ureters. But some conditions and obstructions in the urinary tract can block the normal flow of urine or reverse the urine flow. This can cause a buildup of urine in the kidney, leading to hydronephrosis, or swelling of the kidneys. Hydronephrosis can sometimes be diagnosed before a baby is born on prenatal ultrasound.
Hydronephrosis may lead to a urinary tract infection or cause pain in the abdomen. The two main causes of hydronephrosis include blockage of urine flow (which can occur at different points in the urinary tract) and urine reflux (a reversal of urine flow).
Many times, hydronephrosis resolves on its own without treatment. However, if treatment is needed, most causes of hydronephrosis can be resolved with medications or minor surgery.
All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.
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.
Watch this movie about the urinary system, which produces pee.
The kidneys perform several functions that are essential to health, the most important of which are to filter blood and produce urine.
Urinary tract infections (UTIs) are common in kids. They’re easy to treat and usually clear up in a week or so.
The bean-shaped kidneys, each about the size of a child’s fist, are essential to our health. Their most important role is to filter blood and produce urine.
Doctors order bladder ultrasounds when there’s a concern about bladder problems, such as difficulty urinating or daytime wetting.
A renal ultrasound makes images of your child’s kidneys, ureters, and bladder. Doctors may order this test if they suspect kidney damage, cysts, tumors, kidney stones, or complications from urinary tract infections.
Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.
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