pyloric stenosis Narrowing (stenosis) of the outlet of the stomach so that food cannot pass easily 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.
pyelonephritis Bacterial infection of the kidneys. 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…
pyelogram An X-ray study of the kidneys, especially showing the pelvis (urine-collecting basin), and the ureter.
pyelo See pyelonephritis.
pycnodysostosis An inherited disorder of bone that causes short stature and abnormally dense brittle bones. Pycnodysostosis can be due to a defect in the enzyme cathepsin K. Sometimes spelled pyknodysostosis. The French artist Toulouse-Lautrec is thought to have had this disease. No specific treatment is available.
pyarthrosis See arthritis, septic.
PXE Pseudoxanthoma elasticum.
PWS Prader-Willi syndrome.
PVC Premature ventricular contraction.
PV Polycythemia vera.
pustulosis A highly inflammatory skin condition that results in large, fluid-filled, blister-like areas (pustules). Pustulosis typically occurs on the palms of the hands and/or the soles of the feet. The skin of these areas peels and flakes (exfoliates).
pus A thick, whitish-yellow fluid that results from the accumulation of white blood cells, liquefied tissue, and cellular debris. Pus is commonly a sign of infection or foreign material in the body.