What is hydronephrosis?

Hydronephrosis occurs when the kidneys fill up with too much urine, causing swelling. It can occur while the kidney is developing and is often found by ultrasound before a baby is born. It can also occur if urine becomes blocked at any point while attempting to flow through the urinary tract, like in the case of kidney stones. Hydronephrosis can affect one or both kidneys and can range from mild to severe. In some cases, the condition can resolve on its own, and at other times it may require treatment.

What are the signs and symptoms of hydronephrosis?

Most babies with hydronephrosis have no symptoms. Older children with moderate to severe hydronephrosis may have symptoms, especially during periods the hydronephrosis suddenly worsens.

The main symptom of sudden, worsening hydronephrosis is

  • Severe pain in the lower stomach or side
  • Nausea and/or vomiting

Occasionally, hydronephrosis is associated with other symptoms:

  • Blood in the urine
  • Frequent urinary tract infections

What causes hydronephrosis?

Hydronephrosis can have many causes. Frequently, it is caused by a blockage in the urinary tract. This can be something that a child was born with, or it can be something that suddenly develops, like a kidney stone. Sometimes it is caused when urine refluxes back into the kidney from the bladder. In many cases, the cause of hydronephrosis is not known and requires no treatment.

How is hydronephrosis treated?

Many babies with hydronephrosis will not need any treatment. The condition often clears up on its own before or soon after birth. Other times, the treatment of hydronephrosis depends on the cause and the degree of symptoms. Your medical team at Arkansas Children’s is experienced in treating hydronephrosis and will work with you to come up with the best treatment plan for your child.

If your baby’s hydronephrosis does not get better after birth, treatment may include the following:

  • Close monitoring of the kidneys after birth
  • Antibiotics to prevent an infection
  • Surgery to repair the underlying cause, in severe cases