Polycystic Kidney Disease (PKD) is a kind of genetic kidney disease in which
numerous cysts appear in cortex and medulla of the kidney. According to genetic
methods, it can be divided into two types: one is autosomal dominant type.
Generally, symptoms won’t appear until adulthood. So it is also known as adult
type; the other is autosomal recessive type. This type may have symptoms in
infancy, also known as infancy type. For the patients of this disease, when they
are young, their kidneys are normal or slightly smaller in size and sometimes
small cysts may be found. With the increase of age, the number and size of cysts
will increase gradually, but the process is slow. In most cases, after 30 years
old when the cysts and the kidney become bigger, symptoms will appear. The
common symptoms are as follows.
First, kidney swelling. The kidneys may be five to six times larger than
normal and can have significant differences on both sides. Early kidney swelling
can be found by imaging test. For the severe one, it can be felt by touch.
Second, waist and abdominal discomfort or pain. It is caused by increased
renal capsule tension or traction of renal pedicle vessels and nerves. The
sudden and strong pain is often caused by intracapsular bleeding or secondary
infection. If it is combined with stone or blood clots blocking the ureter,
renal colic will occur.
Third, proteinuria and leukocytes urine. For 20 to 40 year-old patients, 20%
to 40% have mild persistent proteinuria. Generally, 24-hour urine protein is
less than 1g. Leukocytes urine is more common but it’s uncertain that it’s
caused by urinary tract infection.
Fourth, hypertension. It is a common manifestation of this disease at the
early stage and will directly affect the prognosis. It is reported that 60% of
PKD patients without azotemia will have high blood pressure. For PKD patients
with normal kidney function, when they have high blood pressure, their kidney
will be larger than that of those who have normal blood pressure.
Fifth, renal dysfunction. PKD patients won’t have Chronic Renal Failure
before 30 years old. When they are 60 years old, half of them will have lost
their kidney function and need replacement therapy.
