Overview
Hydronephrosis is the swelling of a kidney due to a buildup of urine. This occurs when urine cannot properly drain from the kidney to the bladder due to a blockage or obstruction. The swelling most often affects only one kidney, but it may involve both kidneys in some cases.
Symptoms
Pressure can build up if there’s an obstruction or blockage in the urinary tract. Once the urine builds up for an extended period, the kidney becomes enlarged. The kidney may become so engorged with urine that it starts to press on nearby organs. If left untreated for a prolonged period, the constant pressure can cause the kidneys to permanently lose function.
Common symptoms of hydronephrosis include urinating more frequently and an increased urge to urinate. Other potentially severe symptoms may include:
- Pain in the abdomen or flank
- Nausea
- Vomiting
- Pain when urinating
- fever
Causes
Hydronephrosis is usually caused by another underlying illness or risk factor. Causes of hydronephrosis may include:
- Kidney stone
- Congenital blockage
- Blood clot
- Scarring of tissues (from injury or previous surgery)
- Tumor or cancer
- Enlarged prostate (noncancerous)
- Pregnancy
- Urinary tract infection (UTI)
Diagnosis
Your doctor will ask you a variety of questions to obtain a thorough medical history and health status, focusing on any urinary symptoms you might have. One or more of the following exams and tests are performed for diagnosis:
- Ultrasound
- X-rays
- Computerized tomography (CT)
- Cystoscopy
- Blood and urine tests to check kidney function
Treatment
Hydronephrosis is typically treated by addressing the underlying disease or cause, such as a kidney stone or infection. A kidney stone can pass through by itself or might be large enough to need surgical removal. Infections can be treated with antibiotics.
In cases of severe blockage and hydronephrosis, your doctor might need to do one of the following:
- Insert a ureteral stent, a tube that allows the ureter to drain into the bladder
- Insert a nephrostomy tube, which allows the blocked urine to drain from the kidney
- Prescribe antibiotics to control infection
Severe cases of urinary blockage and hydronephrosis can damage the kidneys and lead to kidney failure. The key to treatment is early diagnosis to avoid permanent damage to the kidneys.
