progeria One of a group of rare genetic disorders that causes premature aging in children. The classic type of progeria is Hutchinson-Gilford progeria syndrome, which is characterized by dwarfism, baldness, pinched nose, small face and small jaw relative to the head size, delayed tooth formation, aged-looking skin, stiffness of joints, hip dislocations, arteriosclerosis, and heart…
progesterone A female hormone, the principal hormone that prepares the uterus to receive and sustain fertilized eggs.
progesterone receptor test A lab test that is used to determine whether breast cancer cells have progesterone receptors. If the cells have progesterone receptors, they may depend on progesterone for growth and usually respond to hormone therapy. Breast cancer cells that do not have progesterone receptors do not need the hormone progesterone to grow and…
progestin Any one of a group of steroid hormones that have the effect of progesterone. See also progesterone.
prognathism An overly prominent jaw. Prognathism may cause no problems or be associated with dental problems. Prognathism is characteristic of some diseases, such as acromegaly.
presentation, breech See breech birth.
presentation, footling See footling birth.
presentation, vertex See vertex birth.
pressure, high blood See hypertension.
pressure, intraocular See intraocular pressure.
pressure, low blood See hypotension.
prevalence The proportion of individuals in a population having a disease or characteristic. Prevalence is a statistical concept referring to the number of cases of a disease that are present in a particular population at a given time, whereas incidence refers to the number of new cases that develop in a given period of time.