Bilateral Hydronephrosis: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Bilateral Hydronephrosis?
A urologist (a doctor who treats the urinary tract) and a nephrologist (a kidney doctor) usually care for people with bilateral hydronephrosis. This condition means swelling in the urine-collecting parts of both kidneys. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is bilateral hydronephrosis?
Bilateral hydronephrosis is the enlargement of the parts of the kidney that collect urine. Bilateral means both sides. It is not a disease itself. It happens when urine cannot drain out of the kidneys, ureters, or bladder, so it backs up and the collecting parts swell. The ureters are the tubes that carry urine from the kidneys to the bladder.
Doctors can find it before a baby is born on a pregnancy ultrasound. In babies and children, repeat urinary tract infections are often the only sign. In some cases the swelling is mild and goes away on its own, usually by the time the child is 3 years old.
Symptoms
Common symptoms in adults may include:
- Back pain.
- Nausea and vomiting.
- Fever.
- Need to urinate often.
- Decreased urine output.
- Blood in the urine.
- Urinary incontinence, which means leaking urine by accident.
A urinary tract infection in a newborn baby can signal a blockage in the kidney. An older child who keeps getting urinary tract infections should be checked for blockage too. Some people have no symptoms at all.
Causes and who gets it
Bilateral hydronephrosis happens when urine cannot drain from the kidneys into the bladder. Disorders linked with it include:
- Sudden or gradual blockage of both kidneys, called obstructive uropathy.
- Bladder outlet obstruction, a blockage that stops the bladder from draining.
- Neurogenic bladder, a poorly working bladder caused by nerve problems.
- Posterior urethral valves, flaps in the urethra that block urine flow in boys.
- Prune belly syndrome, a rare group of birth defects.
- Retroperitoneal fibrosis, abnormal scar tissue that blocks the ureters.
- Ureteropelvic junction obstruction, a blockage where the ureter meets the kidney.
- Vesicoureteral reflux, urine flowing backward from the bladder toward the kidney.
- Uterine prolapse, a dropped uterus that presses on the urinary tract.
In males, an enlarged prostate can also block urine flow. In pregnancy, the growing uterus can press on the ureters. Kidney stones are another common cause of blockage.
How doctors diagnose it
Doctors use imaging tests to show the swelling and find the cause. Tests include:
- Ultrasound of the abdomen or kidneys, a scan that uses sound waves. A pregnancy (fetal) ultrasound can show it before birth.
- CT scan of the abdomen or kidneys, a detailed X-ray scan.
- Renal scan, an imaging test that shows how the kidneys work.
- Voiding cystourethrogram, an X-ray that shows how urine flows through the bladder and urethra.
Doctors also do a physical exam and take a medical history.
Treatment
Treatment first relieves the urine buildup, then fixes the cause of the blockage. Placing a tube into the bladder (a Foley catheter) may open the blockage. Other treatments include draining the bladder, placing tubes through the skin into the kidneys to relieve pressure, and placing a stent (a small tube) through the ureter so urine can flow again. Antibiotics treat infections. Surgery may correct the blockage or reflux, and stones causing blockage can be removed. The underlying cause needs to be found and treated once the buildup is relieved.
When to see a doctor
Call 911 if you have sudden, severe pain in your side, back, or belly, or severe vomiting that will not stop. Get medical help right away for fever with chills, blood in the urine, or much less urine than usual. These can be signs of a blockage or infection that needs urgent care. Untreated blockage can permanently damage the kidneys. People with only one working kidney, a weak immune system, or a kidney transplant need treatment right away.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. For this condition, such a doctor can order urine tests, arrange imaging, and refer you to a urologist or nephrologist. They can also follow your kidney function over time and coordinate care between specialists.
Common questions
Can bilateral hydronephrosis go away on its own?
Yes, in some babies it does. About half of the fetuses found to have hydronephrosis on ultrasound lose the swelling before birth. In children born with it, the swelling sometimes goes away on its own, usually by age 3.
How common is hydronephrosis in babies?
It is found in 1 or 2 out of every 100 pregnancies. Male babies are about twice as likely as female babies to have it.
Does hydronephrosis damage the kidneys?
It can if the blockage is not treated. Permanent kidney damage may result from conditions that cause hydronephrosis. Early treatment protects the kidneys. Kidney failure will occur if only one kidney is working.
How is it treated in newborns?
Treatment depends on how severe it is, whether one or both kidneys are affected, and the cause. Options include watchful waiting with regular tests, antibiotics to prevent or treat urinary tract infections, and surgery if the swelling is severe or gets worse.
Sources
- MedlinePlus Medical Encyclopedia - Bilateral hydronephrosis
- MedlinePlus Medical Encyclopedia - Hydronephrosis of one kidney
- NIDDK (National Institute of Diabetes and Digestive and Kidney Diseases) - Hydronephrosis in Newborns
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
