Webster's New World Medical Dictionary

PV
Polycythemia vera.
PVC
Premature ventricular contraction.
PWS
Prader-Willi syndrome.
PXE
Pseudoxanthoma elasticum.
pyarthrosis
See 
arthritis, septic.
pycnodysostosis
An inherited disorder of bone
that causes short stature and abnormally dense brit-
tle bones. Pycnodysostosis can be due to a defect in
the enzyme cathepsin K. Sometimes spelled pykn-
odysostosis. The French artist Toulouse-Lautrec is
thought to have had this disease. No specific treat-
ment is available.
pyelo
See 
pyelonephritis.
pyelogram
An X-ray study of the kidneys, espe-
cially showing the pelvis (urine-collecting basin),
and the ureter.
pyelonephritis
Bacterial infection of the kid-
neys. Pyelonephritis can be acute or chronic, and it
is most often due to the ascent of bacteria from the
bladder up the ureters to infect the kidneys.
Symptoms include flank (side) pain, fever, shaking
chills, sometimes foul-smelling urine, frequent and
urgent need to urinate, and general malaise.
Tenderness is elicited by gently tapping over the kid-
ney with a fist (percussion). Diagnosis is made via
urinalysis, which reveals white blood cells and bac-
teria in the urine. Usually there is also an increase
in circulating white cells in the blood. Treatment
involves use of appropriate antibiotics. Often called
simply pyelo.
pyloric stenosis
Narrowing (stenosis) of the
outlet of the stomach so that food cannot pass eas-
ily from it into the duodenum. Pyloric stenosis
results in feeding problems and projectile vomiting
in infants. The obstruction can be corrected with a
relatively simple surgical procedure.
pylorus
The outlet of the stomach.