What Is Hydronephrosis?
Hydronephrosis is a condition that typically occurs when the
kidney swells due to the failure of normal drainage of urine from the kidney to
the bladder. This swelling most commonly affects only one kidney, but it can
involve both kidneys. Hydronephrosis isn’t a primary disease. It’s a secondary
condition that results from some other underlying disease. It’s a structural
condition that’s the result of a blockage or obstruction in the urinary tract.
According to the Boston
Children’s Hospital, hydronephrosis affects about one in every 100 babies.
What Are the Symptoms of Hydronephrosis?
Normally, urine flows through the urinary tract with minimal
pressure. Pressure can build up if there’s an obstruction in the urinary tract.
After urine builds up for an extended period, your kidney can enlarge. Your
kidney may become so engorged with urine that it starts to press on nearby organs.
If it’s left untreated for too long, this pressure can cause your kidneys to
lose function permanently.
The length of time you have the obstruction affects your symptoms.
Mild symptoms of hydronephrosis include urinating more frequently and an increase
in the urge to urinate. Other potentially severe symptoms you may experience
- pain in the abdomen or flank
- pain when urinating
- incomplete voiding
- a fever
Interrupting the flow of urine increases your chances of getting
a urinary tract infection (UTI). This is why UTIs are one of the most common complications
of hydronephrosis. Some signs of a UTI include:
- cloudy urine
- painful urination
- burning with urination
- a weak urine stream
- back pain
- bladder pain
- a fever
If you see signs of hydronephrosis, schedule an appointment with
your doctor to talk about your symptoms. Untreated UTIs may lead to more
serious conditions such as pyelonephritis, or infection of the kidney, and
sepsis, which is an infection in the bloodstream or blood poisoning.
What Causes Hydronephrosis?
Hydronephrosis isn’t a disease. Instead, it can be due to internal
and external conditions that affect the kidney and the urinary collecting
One of the most common of causes of hydronephrosis is acute unilateral obstructive uropathy. This is a sudden
development of an obstruction in one of your ureters, which are the tubes that connect your kidneys to your
bladder. The most common cause for this blockage is a kidney stone, but
scarring and blood clots can also cause acute unilateral obstructive uropathy.
A blocked ureter can cause urine to go back up into the kidney, which causes
swelling. This backflow of urine is known as vesicoureteric reflux (VUR).
Other causes of blockage may include:
- a kink in the ureteropelvic junction, which is
where the ureter meets the pelvis of the kidney
- an enlarged prostate gland in men, which can be
due to BPH or prostatitis
- pregnancy, which causes a compression due to a
- tumors in or near the ureter
- a narrowing of the ureter from an injury or
How Is Hydronephrosis Diagnosed?
Getting as early a diagnosis as possible is extremely important. Your
kidneys could be permanently damaged if your condition is left untreated for
too long. Your doctor will likely begin by getting an overall assessment of
your health status and then focus on any urinary symptoms you might have. Your
doctor may be able to feel your enlarged kidney by gently massaging the abdomen
and flank area.
Your doctor may use a catheter to drain some of the urine from
your bladder. If they’re unable to release a large amount of urine this way, it
could mean that your obstruction is in your bladder or your urethra. The urethra is a tube that carries
urine from your bladder to the outside of your body. Your doctor may also want
to perform a renal ultrasound or CT scan to get a closer look at the extent of
the swelling and to possibly locate the area of the blockage. Both of these
procedures let your doctor view an image of the inside of your body, but the
renal ultrasound is generally considered as the gold standard for the diagnosis
of hydronephrosis. It allows your doctor to get a closer look at your kidney.
What Are the Treatment Options for
Treatment for hydronephrosis primarily focuses on getting rid of
whatever is blocking the flow of urine. The treatment option your doctor
chooses for you will depend on the cause of your obstruction.
If a blocked
ureter is causing your condition, your doctor might need to do any of
- insert a ureteral stent, which is a tube that
allows the ureter to drain into the bladder
- insert a nephrostomy tube, which allows the
blocked urine to drain through the back
- prescribe antibiotics to control infection
Your doctor might remove the obstruction with surgery. If something
like scar tissue or a blood clot is causing the blockage, your doctor might
remove the affected area completely. They can then reconnect the healthy ends
of your ureter to restore normal urine flow.
If the cause of your hydronephrosis is a kidney stone, you may
need surgery to remove it. To do this, your doctor might perform endoscopic
surgery, which involves using tiny instruments to perform the procedure. This
allows your doctor to make smaller incisions, drastically reducing your healing
and recovery time. Your doctor might also prescribe you antibiotics. This will
help ensure you don’t develop a kidney infection.
What Is the Long-Term Outlook?
If you receive treatment early, your outlook is good. Removal of
the obstruction is essential for your kidney to return to normal functioning.
If your hydronephrosis requires surgery, you have a 95 percent chance of having
a full recovery, according to the Boston