What Is Hyrdonephrosis?
Hydronephrosis is the swelling of a kidney due to obstruction to the flow of urine.
Hydronephrosis may or may not cause symptoms. The main symptom is pain, either in the side and back (known as flank pain), abdomen or groin. Other symptoms can include pain during urination, other problems with urination (increased urge or frequency, incomplete urination, incontinence), nausea and fever.

Common Causes Of Hydronephrosis:
- Kidney stone
- Congenital blockage
- Blood clot
- Scarring of tissue (from injury or previous surgery)
- Tumor or cancer of urinary bladder, cervical, colon, or prostate
- Enlarged prostate
- Pregnancy
- Urinary tract infection
How Is Hydronephrosis Diagnosed?
An ultrasound is typically used to confirm a diagnosis. This procedure uses sound waves to create an image of your kidneys. A doctor can also confirm a diagnosis with x-rays, computerized tomography (CT) and magnetic resonance imaging (MRI). Diagnosis could also involve a cystoscopy, which uses a long tube with a light and camera at the end (cytoscope) that allows the doctor to look inside the bladder and urethra.
Blood and urine tests can also check kidney function. The doctor can also check for blood in the urine, which can be caused by a kidney stone, infection or other factor.
How Is Hydronephrosis Treated?
Hydronephrosis is usually treated by addressing the underlying disease or cause, such as a kidney stone or infection. Some cases can be resolved without surgery. Infections can be treated with antibiotics. A kidney stone can pass through by itself or might be severe enough to require removal with surgery.
In cases of severe blockage and hydronephrosis, excess urine may need to be removed using either a catheter to drain urine from the bladder or a special tube called a nephrostomy that drains urine from the kidney. The key to treatment is to get it addressed as soon as possible in order to avoid any permanent damage to the kidneys.
Severe cases of urinary blockage and hydronephrosis can damage the kidneys and lead to kidney failure. If kidney failure occurs, treatment will be needed with either dialysis or a kidney transplant. However, most people can recover from hydronephrosis if treated promptly.