What Causes Swollen Kidneys in Adults?

A buildup of urine can cause swollen kidneys in adults, according to the National Kidney Foundation. The name of this condition is hydronephrosis, and it occurs when the urine cannot drain from the kidney to the bladder properly due to a blockage. Usually only one kidney swells, notes Healthline.

A kidney stone, a blood clot, scar tissue, a tumor or an enlarged prostate can cause this blockage, explains the National Kidney Foundation. Pregnancy or any type of inflammation of the urinary tract can cause the blockage as well.

Symptoms may or may not be present, notes the National Kidney Foundation. When present, symptoms may include pain in the flank, abdomen or groin as well as nausea and fever. Painful urination, frequent urination, urgency of urination and urinary tract infection are other possible symptoms of hydronephrosis, adds Healthline.

Early treatment of this condition is critical to avoid permanent damage to the affected kidney, warns Healthline. The doctor may insert a catheter to drain urine from the bladder, or he may insert a tube to drain urine from the kidney, states the National Kidney Foundation. Treatment involves correcting the underlying problem. Antibiotics can clear up a urinary tract infection, but a patient may require surgery to remove a kidney stone, blood clot, scar tissue or tumor.