Skip to main content


Medically reviewed by Last updated on May 6, 2024.

What is hydronephrosis?

Hydronephrosis is swelling in one or both kidneys caused by urine buildup. Urine normally flows from the kidneys to the bladder through tubes called ureters. A blockage in the ureters can prevent urine from flowing properly. Urine flow may also be prevented or slowed if your kidneys do not work correctly. Urine flows back into your urinary tract. Pressure builds up in the kidney and causes swelling.


What increases my risk for hydronephrosis?

What are the signs and symptoms of hydronephrosis?

You may have no signs or symptoms, or you may have any of the following:

How is hydronephrosis diagnosed?

Your healthcare provider will examine you and ask you about your signs and symptoms. Your provider may also feel your abdomen or pelvis for any pain or swelling. You may also need any of the following:

How is hydronephrosis treated?

Treatment may help keep your kidneys healthy, and prevent infection. You may need the following:

What are the risks of hydronephrosis?

Swelling in one or both kidneys from too much urine buildup may lead to long-term kidney damage. Partial blockages may cause loss of urine control. Severe hydronephrosis may cause a blood infection called sepsis. Sepsis is toxin (poison) buildup in your blood. It happens when your kidneys cannot flush toxins out of your body. It could also paralyze your intestines. Your kidneys could fail without treatment. These conditions may be life-threatening.

When should I contact my healthcare provider?

When should I seek immediate care?

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

© Copyright Merative 2024 Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.