Hydronephrosis (Kidney Swelling) - Diagnosis & Treatment

How is hydronephrosis diagnosed?

Hydronephrosis may be detected through routine prenatal ultrasound examination before your child's birth. An ultrasound will show the shape and size of your baby’s kidneys and the amount of amniotic fluid. It can also reveal obstructions in the urinary system.

For children, your doctor will recommend a series of tests to make an accurate diagnosis of their kidney condition. These may include:


The first test will likely be a renal ultrasound examination. Through the images taken, the doctor can closely examine your child’s kidneys. The findings from the ultrasound will help determine if your child needs further tests.

Voiding cystourethrogram

This X-ray imaging procedure takes a close look at the bladder to examine it as it empties. This helps determine if there is urine reflux, which is one of the common causes of hydronephrosis.

Voiding cystourethrogram can also check if there is blockage in the urethra. Using a catheter, the child’s bladder will be filled with a liquid dye that contains iodine. The X-ray images will show the flow of the liquid dye as the bladder fills and the child urinates.

Renal scan

Your doctor may recommend a renal or kidney scan to check your child's kidneys and examine any blockage in the urinary tract.

In a renal scan, a small amount of radioactive material will be injected into the bloodstream. With the help of a special camera, the doctor will check how the kidneys function as the radioactive material moves through them.

How is hydronephrosis treated?

Depending on the diagnosis, your baby may not need any treatment as the baby's kidney can get better over time.

If your child's upper end of the ureter is partially blocked, your doctor may recommend surgery to relieve pressure on the kidney.

Speak to a paediatrician to learn more about hydronephrosis and treatment options for your child.

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