Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «P»:
Pestis: The plague. An infectious disease due to a
bacteria called Yersinia pestis.
Y. pestis mainly infects rats and other rodents. Rodents are the
prime reservoir for the bacteria. Fleas function as the prime vectors
carrying the bacteria from one species to another. The fleas bite the
PET scan: The popular name (and abbreviation) of Positron Emission Tomography....
Petasites hybridus: See: Butterbur....
Petasites vulgaris: See: Butterbur....
Petechiae: Pinpoint flat round red spots under the skin surface caused by intradermal hemorrhage (bleeding into the skin). Petechiae are red because they contain red blood that has leaked from the capillaries into the skin. Petechiae are quite tiny (less than 3 millimeters in diameter) and do not bl...
Peter Mansfield: See: Mansfield, Peter....
Peter Pan syndrome
Peter Pan syndrome: Term coined by pop psychology author Dan Kiley in his book "Peter Pan syndrome: Men Who Have Never Grown Up."
Peter Pan is in reference to J. M. Barrie's classic 1904 play in which a boy who refuses to grow up teaches Wendy and her younger brothers how to fly and then it's off t...
Petit mal: A form of epilepsy with very brief, unannounced lapses
in consciousness. A petit mal seizure involves a brief loss of awareness, which can be accompanied by blinking or mouth twitching. Petit mal seizures have a very characteristic appearance on an electroencephalogram (EEG). Petit mal (l...
Peutz-Jeghers syndrome: A cancer genetic disorder characterized by freckle-like spots on the lips, mouth and fingers and polyps in the intestines. Patients are at increased risk for developing cancer of the esophagus, stomach, colon, rectum, breast, ovary, testis and pancreas.
The polyps may occur ...
Peyronie's disease: A condition of uncertain cause in which a plaque (a hard lump) forms on the upper or lower side of the penis in layers containing erectile tissue resulting sometimes in severe curvature of the penis. Surgery is usually only recommended in long-term cases in which the deformity ca...
Pfeiffer syndrome: A syndrome of craniosynostosis (premature fusion of the cranial sutures) due to mutation in FGFR (fibroblast growth factor receptor) characterized by bulging eyes (proptosis) due to shallow eye sockets, underdevelopment of the midface and broad short thumbs and big toes.
PFOA: Perfluorooctanoic acid. See: Perfluorinated acid....
PFT: Pulmonary function test, a test designed to measure how well the lungs are working. PFTs gauge how the lungs are doing their jobs -- of expanding and contracting (when a person inhales and exhales) and of exchanging oxygen and carbon dioxide efficiently between the air (or other gases) within t...
PGA (polyglandular autoimmune syndrome)
PGA (polyglandular autoimmune syndrome): A genetic autoimmune disease with an extraordinary array of clinical features but characterized most often by at least 2 of the following 3 findings: hypoparathyroidism -- underfunction of the parathyroid glands which control calcium,
candidiasis (yeast infe...
PGE-2: Prostaglandin E2....