Dictionary

Enter a word or phrase below to search our online dictionary of over 1,300 general medical terms, or click on a letter of the alphabet to view all terms beginning with that letter:

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Search for 'P'

Phrase Definition
Paget's disease 1. A type of cancer usually involving the breast's larger ducts, areola and nipples. 2. A disease characterized by weakened and deformed bones.
palate The roof of the mouth.
palliative Controlling symptoms without curing the disease.
pallor Pale appearance of the skin.
palpate To feel with the fingers.
palpebra The eyelid.
palpitation A sensation that the heart is beating too rapidly or strongly.
palsy See paralysis.
panacea A remedy for all diseases.
pancreas A gland located below and behind the stomach and liver that produces insulin and glucagon, the hormones involved in carbohydrate metabolism.
pancreatitis Inflammation of the pancreas.
pandemic A widespread epidemic.
panic A sudden attack of anxiety.
papilla A small nipple-shaped projection.
papilledema Swelling of the optic disk. May be due to an increase of pressure in the skull.
papilloma A benign tumor of the skin or mucous membranes. A wart.
papule A solid, raised skin lesion.
para-aminobenzoic acid PABA, a substance used in suntan lotion and used clinically to treat rickettsial diseases.
paracentesis Surgical removal of fluid from a cavity.
parainfluenza virus One of a group of viruses that cause a variety of upper respiratory diseases.
paralysis Inability to move parts of the body.
paranasal sinuses The mucosa-lined cavities in the bones of the skull that open into the passages of the nose.
paranoia A mental disorder characterized by a belief that others are out to get you.
paraplegia Inability to feel or move the legs.
parasite An organism that lives on or in the tissues of another organism and draws its nourishment from the host.
paraspadias A developmental abnormality in which the urethra opens along one side of the penis.
parathyroid glands Two pair of small glands situated next to or in the thyroid gland that are involved in the metabolism of calcium and phosphorus.
parenteral Inside the body, but outside the intestines.
paresis Partial or slight loss of feeling or movement.
paresthesia An abnormal sensation of burning or prickling on the skin, caused by a disorder of the nervous system.
Parkinson's disease A progressive disease of the brain. Characterized by tremors and muscle stiffness.
parotid glands The largest of the salivary glands, located near the ears.
paroxysm A sudden attack, or raised level of intensity, of symptoms.
pasteurization Heating milk or other substances to a temperature of 140ºF for 30 minutes to kill harmful bacteria.
patella The kneecap.
pathogen Any agent that causes disease.
pathology The study of changes caused by disease.
pectoral Having to do with the chest or breast.
pectus carinatum An abnormally prominent sternum or breastbone. Also called pigeon breast.
pectus excavatum A defect of the sternum that's present at birth.
pedal Having to do with the feet.
pediatrics The branch of medicine that deals with the development and care of infants and children.
pediculosis Infestation with lice.
pelvis The bony structure formed by the sacrum, coccyx, ilium, pubis and ischium.
pemphigus A skin condition characterized by large blisters.
pepsin A digestive enzyme found in the stomach.
peptic Having to do with the stomach.
percutaneous Introduced through the skin.
perforation A hole or break through a membrane or the wall of an organ.
pericarditis Inflammation of the sac that surrounds the heart.
pericardium The fibrous sac the heart.
perineum The pelvic floor. In females, the region from the vagina to the anus. In males, the region from the base of the scrotum to the anus.
periodontitis Inflammation of the tissues around the teeth.
periosteum The connective tissue covering the bones of the body.
peripheral At or near the surface of the body. Located away from the center structure.
peristalsis The waves of contraction and relaxation of the smooth muscle of the digestive tract.
peritoneum The membrane lining the walls of the abdominal and pelvic cavity.
peritonitis Inflammation of the peritoneum.
pernicious Fatal.
pernicious anemia Anemia due to vitamin B12 deficiency.
pertussis See whooping cough.
petit mal A mild seizure with a momentary loss of consciousness.
phagocyte Any cell that destroys invading microorganisms.
phagomania An obsession with eating.
pharmacist A person licensed to mix and dispense drugs.
pharyngitis Inflammation of the pharynx. Also called a sore throat.
pharynx The cavity of the canal leading from the mouth and nasal passages to the larynx and the esophagus.
phenylalanine An essential amino acid occurring in proteins. A small amount of phenylalanine is necessary in the diet to make the proteins that form human tissues.
phenylketonuria (PKU) A rare inherited disorder. Causes an inability to metabolize phenylalanine, an amino acid that's a common part of many proteins that form tissues in the body. Left untreated, it causes severe mental retardation in infants.
phimosis Excessive tightness of the foreskin of the penis.
phlebitis Inflammation of a vein.
phlebotomy Withdrawal of blood from a vein.
phlegm Mucus, especially mucus produced by the lungs during inflammation or infection.
phobia Any persistent, unreasonable abnormal fear.
phonation Making vocal sounds.
photophobia Abnormal intolerance of light.
physician A doctor. An authorized practitioner of medicine.
physiology The branch of medicine that deals with the function of the various parts of the living organism.
pigeon toe A foot condition where the toes turn in.
piles See hemorrhoids.
pilus Hair.
pimple A small, elevated skin lesion
pinguecula A yellowish spot on the cornea of the eye that sometimes occurs in the elderly.
pink eye Inflammation of the conjunctiva. Also called conjunctivitis.
pinna The part of the ear that's projected outside of the head.
pinworm A parasite, Enterobius vermicularis, that can cause intense itching around the anus.
pituitary gland The gland that secretes hormones that influence body growth, metabolism and the function of other endocrine glands.
pityriasis A skin condition in which the skin forms thin, dry scales.
placebo A harmless substance that resembles a medicine; often used to test the effectiveness of medicines.
placenta A spongy structure that grows on the uterine wall during pregnancy and provides nutrition to the fetus.
plague 1. Any contagious epidemic disease that is deadly. 2. An infectious disease caused by Yersinia pestis that can be spread from animals to humans and is normally spread to humans by fleas (called bubonic plague) or from person to person by respiratory droplets (called pnenmonic plague). Both forms have a high death rate.
plantar Having to do with the sole of the foot.
plasma The fluid portion of the blood.
platelet A thrombocyte, the smallest of the formed components of blood, associated with blood clotting.
pleura The membrane surrounding the lungs and lining the walls of the chest cavity.
pleurisy Inflammation of the pleura.
plexus A network of nerves or veins.
plumbism Chronic lead poisoning.
pneumoconiosis Any of several lung diseases caused by inhaling particles of industrial substances.
pneumonia Acute inflammation or infection of the lungs.
pneumothorax The buildup of air or gas in the chest cavity. May cause lung collapse.
podiatry The branch of medicine that pertains to the foot and its ailments.
poison A substance that causes illness or death when eaten, drunk or absorbed into the body.
poliomyelitis An acute, infectious disease that attacks the central nervous system. Sometimes causes paralysis that can result in permanent deformities. Vaccines are available. Also called polio.
pollen The male fertilizing element of flowering plants.
polycythemia Abnormal increase in the number of red blood cells or hematocrit.
polydactyly Extra fingers or toes.
polydipsia Excessive thirst.
polyhidrosis Excessive sweating.
polyp A growth extending outward from a mucous membrane.
polypectomy Surgical removal of a polyp.
polyuria Excessive, frequent urination.
pons A piece of connecting tissue, specifically the bridge of white matter at the base of the brain.
popliteal Having to do with the area behind the knee.
pore A small opening.
posterior At or toward the back.
postoperative After surgery.
postpartum After childbirth.
preeclampsia A complication of pregnancy. The development of hypertension with protein in the urine, buildup of fluid (edema) or both.
premenstrual syndrome PMS. Headache, irritability, edema (swelling), abdominal discomfort, pelvic pain and nausea in the days before the start of the menstrual periods of some women.
prepuce A covering fold of skin, such as the foreskin of the penis.
presbyopia A form of farsightedness occurring after middle age. Caused by a loss of elasticity of the crystalline lens with age.
prescription A physician's written direction for preparation and use of a medicine.
prevalence The number of cases of a specific disease in a given population at a certain point in time.
proctitis Inflammation of the rectum.
prodrome Symptoms marking the onset of an illness.
progeny Children.
progeria Premature aging.
progesterone A steroid produced by the ovaries to prepare the uterus for the reception and development of the fertilized ovum (egg).
prognosis The probable outcome of a disease.
prolactin The pituitary hormone that promotes the growth of breast tissue and encourages the production of milk.
prolapse The falling or slipping out of place of an internal organ, such as when the uterus falls into the vagina.
prostate A male reproductive gland that surrounds the neck of the bladder and the urethra.
prosthesis An artificial substitute for a missing body part.
protein An organic compound composed primarily of amino acids.
proteinuria Protein in the urine.
pruritus Itching.
psoriasis Chronic, recurring skin disease characterized by red, inflamed patches covered with scales.
psychiatry The branch of medicine that deals with the diagnosis, treatment and prevention of mental disorders.
psychoanalysis A technique developed by Sigmund Freud for the diagnosis and treatment of mental disorders.
psychology The scientific study of mental processes and behavior.
psychopath A person with a mental disorder characterized by the conspicuous disregard for the rights and needs of others, the lack of remorse and the lack of empathy for others.
psychosis A mental disorder with serious derangement of the thinking process, often including delusions or hallucinations.
ptilosis Shedding of the eyelashes.
ptosis A prolapse or falling of some organ or structure, especially the drooping of a paralyzed upper eyelid.
puberty The stage of life during which the secondary sexual characteristics begin to develop and sexual reproduction becomes possible.
pubis The most forward bone of the pelvis.
puerperium The period of time just after childbirth.
pulmonary Having to do with the lungs.
pulse The heartbeat as felt through the walls of an artery.
puncture A wound produced by a pointed object.
pupil The opening in the center of the iris.
purpura Movement of blood into the soft tissues, producing bruises.
purulent Containing pus.
pus A thick fluid produced in certain infections.
pustule A small pus-containing blister.
pyelitis Inflammation of the urine-collecting system within the kidney.
pyelonephritis Kidney infection.
pylorus The junction of the stomach and the small intestine.
pyodermatitis Skin infection producing pus.
pyridoxine Vitamin B6, sometimes used to treat nausea in pregnancy or to manage premenstrual syndrome symptoms.
pyrogen Something that causes fever.