Obstructive Nephropathy
What is it?
Obstructive nephropathy is a disease or abnormality of
the kidneys that is a complication of a condition called
obstructive uropathy. Obstructive uropathy is a blockage
of the flow of urine out of the bladder and urethra.
Who gets it?
Obstructive nephropathy can occur in men or women. Men
with enlarged prostates or prostate cancer are at a higher
risk for developing obstructive nephropathy.
What causes it?
In men, blockages are usually caused by an enlarged
prostate. In women, it is much less common, but can be
caused by a condition known as bladder cystocele. Other
causes can include bladder tumors, tumors of the prostate,
tumors or other structures around the bladder neck or
urethra, a narrowing (stricture) in any part of the
urinary tract, or kidney stones or bladder stones. The
blockage causes urine to back up into the kidneys, which
become overfilled with fluid, called hydronephrosis. This
not only places pressure on the kidneys, but can cause
repeated urinary tract infections (UTIs). Blockages in the
urinary tract can also reduce the blood supply to the
kidneys. Any of these conditions can damage the kidneys
and affect their function, resulting in obstructive
nephropathy.
What are the symptoms?
Patients with obstructive nephropathy experience a
change in normal kidney function. Because this condition
arises from obstructive uropathy, it is important to
recognize these symptoms and seek treatment before it
progresses to kidney failure. The symptoms of obstructive
uropathy include a decreased or increased urine output,
difficulty beginning to urinate (urinary hesitancy), or an
abnormal urine flow, such as dribbling after urinating.
Some patients have difficulty controlling the urine flow
(incontinence). The patient may notice a decrease in the
force of the urinary stream, or a small, weak stream. He
or she may also notice an increased urgency to urinate,
especially at night, or a feeling that the bladder has not
been completely emptied. Burning or stinging with
urination, blood in the urine, or an abnormal color to the
urine can also be symptoms. Pain may occur on both sides,
in the kidney area. These symptoms can be acute, meaning
they occur suddenly, or build up gradually. The damage
that causes obstructive nephropathy can be reversed if
diagnosed and treated promptly. However, obstructive
nephropathy can eventually result in complete kidney
failure. When the kidneys fail, toxins and fluids build up
in the bloodstream. The excess fluid causes swelling
(edema), usually in the hands, feet, face, and abdomen.
The extra fluid also causes the blood pressure to rise.
How is it diagnosed?
To diagnose obstructive nephropathy your doctor will
ask about your medical history and perform a complete
physical examination. It is important for your doctor to
know if you have a history of urinary tract infections (UTIs),
kidney stones, or problems with urinary output, or a
family history of prostate or pelvic cancer. Your doctor
will feel your abdominal area for enlargement of the
kidneys and bladder. By inserting a flexible tube called a
catheter into your bladder, your doctor can check urine
output to determine the location of the blockage. Your
doctor will order laboratory tests of urine and blood
samples. Patients with nephropathy will have higher levels
of waste products such as creatinine and urea in the
blood. Your doctor will also look for signs of a urinary
tract infection, and a build up of acids in the blood
called metabolic acidosis, which occurs because the
kidneys are not functioning correctly. A variety of scans
can confirm the source of the blockage. These include a
renal scan, ultrasound of the kidneys, and an abdominal
computed tomography (CT) scan. A diagnostic procedure
called an intravenous pyelogram may also be used.
What is the treatment?
To treat obstructive nephropathy, your doctor will
remove the obstruction as quickly as possible. The method
for removing the obstruction depends upon its type and
location. Obstructions caused by prostate enlargement or
cancer, as well as lower urinary tract obstructions,
require surgery. Some kidney stones can be passed in the
urine, which is aided by increasing fluid intake. Others
must be surgically removed, or may be broken up with sound
waves and a procedure called lithotripsy. Once the
obstruction is relieved, urine can drain from the kidneys
and eventually from the body. A catheter may be used to
drain the urine. Once kidney failure has occurred, waste
products must be removed from the bloodstream for the
kidneys through a process called dialysis.
Self-care tips
Obstructive nephropathy can be prevented if you
recognize the signs of an obstruction and seek treatment
immediately before the condition progresses. See your
doctor if you notice any changes in urinary output, or if
you suffer from frequent urinary tract infections.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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