Hydronephrosis is a swelling in the kidney usually due to a blockage that prevents urine from flowing into the bladder. The blockage typically occurs in the upper section of the urinary tract as a result of an abnormal narrowing of the ureter. Complications from hydronephrosis may include decreased kidney function. Hydronephrosis is much more common in males than in females.
Causes of Hydronephrosis
Causes of hydronephrosis may vary based on the location of the swelling. Most prenatal cases that are diagnosed are usually due to a congenital abnormality. Other causes of hydronephrosis may be the result of the following:
- Kidney or bladder stones
- Urethral stricture
- Scarring from previous surgeries
- Cancer or tumors within the prostate, cervix or bladder
Symptoms of Hydronephrosis
Symptoms of hydronephrosis may not develop until months or years after a diagnosis has been made, however, some patients with hydronephrosis may experience:
- Back pain
- Pain while urinating
- Blood in the urine
Some patients with hydronephrosis may not experience any symptoms at all.
Diagnosis of Hydronephrosis
Most cases of hydronephrosis are diagnosed during a prenatal ultrasound. Once the child is born, the specific type of blockage can be identified. In adults and children, in addition to a physical examination, diagnostic tests may include:
- Blood test
- CT scan
- X-ray of the kidneys and ureters
Treatment of Hydronephrosis
The treatment of hydronephrosis may vary, depending on the cause and severity of the condition. Mild cases may only require regular monitoring with a renal ultrasound to ensure that the condition does not worsen. More serious cases may require antibiotics or the insertion of a catheter into the bladder to drain urine. Some cases may require surgery to correct the condition. Surgery for hydronephrosis relieves the obstruction and allows urine to flow from the kidneys.
Severe cases of hydronephrosis, diagnosed through a prenatal ultrasound, may require fetal intervention. The fetus is treated while still in the womb through a surgical procedure that places a shunt in the bladder to drain it. This procedure is performed in life-threatening cases in which the bladder and both kidneys cannot be drained.
- National Institutes of Health
- Centers for Disease Control and Prevention
- Eunice Kennedy Shriver National Institute of Child Health and Human Development
- U.S. Department of Health & Human Services
- U.S. National Library of Medicine