Draining the urine
The first stage in treating hydronephrosis is to drain the urine out of your kidneys.
This will help ease your pain and prevent any further damage to your kidneys.
A thin tube called a catheter may be inserted into your bladder through your urethra (the tube that carries urine out of the body) or directly into your kidney through a small cut in your skin.
Read more about urinary catheterisation.
In a few cases where one of the kidneys has already been severely damaged, it may be better to remove the affected kidney.
Most people can function normally with just one working kidney, which will not usually have a significant effect on your health or lifestyle.
Treating the underlying cause
Once the pressure on your kidneys has been relieved, the cause of the build-up of urine may need to be treated.
Some possible causes and their treatments are described below:
- kidney stones can be removed during an operation or broken up using sound waves – read more about treating kidney stones
- an enlarged prostate can be treated with medication or surgery to remove some of the prostate – read more about treating prostate enlargement
- narrowing of the ureter (the tube that runs from the kidney to the bladder) can be treated by inserting a hollow plastic tube called a stent, which allows urine to flow through the narrowed section – this can often be done without making cuts in your skin
- cancer that's causing hydronephrosis may be treated using chemotherapy, radiotherapy or surgery to remove the cancerous tissue
If hydronephrosis occurs because you're pregnant, you will not usually need any treatment because the condition will pass within a few weeks of giving birth.
In the meantime, catheters can be regularly used to drain urine from the kidneys.
Painkillers and antibiotics can also be given if you're in pain or develop a UTI.
Treating hydronephrosis in babies
Most babies diagnosed with hydronephrosis before they're born (antenatal hydronephrosis) will not need any treatment because the condition will improve before they're born or within a few months of their birth.
There's usually no risk to you or your child, so labour should not need to be started early.
After the birth, your baby may be examined to check for any obvious problems, such as swollen kidneys, but normally you'll be able to take them home with you.
Your baby may need to return to hospital for some scans during the next few weeks to check there aren't any continuing problems.
These scans may include:
- an ultrasound scan – where sound waves are used to create a picture of your baby's kidneys
- a micturating cystourethrogram (MCUG) – where a thin tube is used to pass a special type of liquid that shows up clearly on X-rays into your baby's bladder while a series of X-rays are taken
- a dimercaptosuccinic acid (DMSA) scan or MAG-3 scan – where your baby is injected with a substance that shows up on a special device called a gamma camera; the camera is then used to take pictures of your child's kidneys
In most children, hydronephrosis will get better as they get older. But until scans show there's no longer a problem, your child may need to take antibiotics to reduce their chances of developing a UTI as the urine inside their kidneys can make them more vulnerable to infection.
If hydronephrosis does not get better by itself, your child may need to keep taking antibiotics. Occasionally, surgery may be recommended to treat the underlying cause of the condition.