Medical terms - Letter P | MedicalVocabulary.org

P arm of a chromosome

The short arm of a chromosome. The 'p' comes from the French 'petit' meaning small. All human chromosomes have 2 arms - the p (short) arm and the q (long) arm - that are separated from each other only by a primary…
P in biochemistry

The abbreviation for protein. For example, p53 is a protein (53 kilodaltons in size).
P in population genetics

The frequency of the more common of two different alternative (allelic) versions of a gene. (The frequency of less common allele is q).
P. acnes

See: Propionibacterium acnes
P. cepacia

Pseudomonas cepacia, a bacterium now known as Burkholderia cepacia. See: Burkholderia cepacia
P.c.

Abbreviation meaning after meals (from the Latin 'post cibum', after meals). One of a number of hallowed abbreviations of Latin terms that have traditionally been used in prescriptions. Some others: > >a.c. = before…
P.o.

Abbreviation meaning by mouth, orally (from the Latin 'per os', by mouth). One of a number of hallowed abbreviations of Latin terms that have traditionally been used in prescriptions. Some others: > >a.c. = before meals…
P.r.n.

Abbreviation meaning 'when necessary' (from the Latin 'pro re nata', for an occasion that has arisen, as circumstances require, as needed). One of a number of hallowed abbreviations of Latin terms that have…
P53

A tumor suppressor. The designation 'p53' stands for 'protein 53 kilodaltons' in size. p53 is a specific protein produced by a gene that functions to suppress the growth of tumors. The p53 gene is the most commonly…
PA (physician assistant)

>Medical histories and physical examinations: a PA is usually can perform histories and physical examinations that do not go beyond a particular level. >Laboratory tests: a PA can order any test which he or she is…
PA (posteroanterior)

In anatomy, PA stands for posteroanterior: from back-to-front. For example, a PA X-ray of the chest is taken from back-to-front. PA in this respect is the opposite of AP which stands for anteroposterior: from…
PA X-ray

An X-ray picture in which the beams pass from back-to-front (posteroanterior). As opposed to an AP (anteroposterior) film in which the rays pass through the body from front-to-back
PA-C

Physician Assistant - Certified
Pacemaker

Pacemaker: A system that sends electrical impulses to the heart in order to set the heart rhythm. The pacemaker can be the normal 'natural' pacemaker of the heart or it can be an electronic device. The natural pacemaker…
Pacemaker, artificial

A device that uses electrical impulses to regulate the heart rhythm or to reproduce that rhythm. An internal pacemaker is one in which the electrodes into the heart, the electronic circuitry and the power supply are…
Pacemaker, implantable

A device that uses electrical impulses to regulate the heart rhythm or to reproduce that rhythm. An internal pacemaker is one in which the electrodes into the heart, the electronic circuitry and the power supply are…
Pacemaker, internal

A device that uses electrical impulses to regulate the heart rhythm or to reproduce that rhythm. An internal pacemaker is one in which the electrodes into the heart, the electronic circuitry and the power supply are…
Pacemaker, natural

Pacemaker, natural: The natural pacemaker of the heart is the sinus node, one of the major elements in the cardiac conduction system, the system that controls the heart rate. This stunningly designed system generates…
Pachy- (prefix)

Thick. As in pachydactyly (thick fingers), pachydermatous (thick fingers) and pachyonychia (thick nails). From the Greek pachys, thick
Pachydactyly

Thick fingers or toes. A feature, for example, of neurofibromatosis. From the Greek pachys, thick + daktylos, finger or toe
Pachyderma

Thick skin, like that of a pachyderm (an elephant, rhinoceros, or hippopotamus). From the Greek pachydermos meaning 'thick skin' from pachys meaning 'thick' + derma meaning 'skin.' The adjective is pachydermatous
Pachydermatous

1. Thick-skinned like a pachyderm (an elephant, rhinoceros, or hippopotamus). 2. By extension, insensitive
Pachymeninges

The dura. From pachy- (thick) + -meninges (membranes). The singular is pachymeninx
Pachymeninx

The dura. From pachy- (thick) + -meninx (membrane). The plural is pachymeninges
Pachyonychia

Elephant nail, a fingernail or toenail that is abnormally thick. From the Greek pachys, thick + onyx, nail = thick nail
Pachyonychia congenita of the Jadassohn-Lewandowsk

E: This is a type of pachyonychia congenita (elephant nails from birth). The characteristic features include: > >Abnormally thick curved nails (onychogryposis) >Thickening of the skin (hyperkeratosis) of the palms…
Pachyonychia congenita with natal teeth

This is a type of pachyonychia congenita (elephant nails from birth) in which teeth are evident at birth. It is called the Jadassohn-Lewandowski syndrome. The characteristic features include: > >Abnormally thick curved…
Pachyonychia congenita, type 1

This is a form of pachyonychia congenita (elephant nails from birth) in which teeth are evident at birth. It is called the Jadassohn-Lewandowski syndrome. The characteristic features include: > >Abnormally thick curved…
Pacifier

An artificial nipple, usually made of plastic, upon which an infant can suck to gain some solace and quiet down. A pacifier is called by other names in other countries including a 'dummy' in the U.K. Pacifiers have been…
Pacing, diaphragm

See: Diaphragm pacing
PAD

Peripheral artery disease
Paediatrics

Pediatrics in Great Britain.
Page kidney

Chronic longstanding compression of the kidney resulting in hypertension. The kidney is compressed, most often, by a post-traumatic subcapsular hematoma (a collection of blood beneath the capsule surrounding the kidney)…
Paget disease

A chronic bone disorder that typically results in enlarged, deformed bones due to excessive breakdown and formation of bone tissue that can cause bones to weaken and may result in bone pain, arthritis, deformities or…
Paget disease of the breast

The combination of scaly skin changes of the nipple resembling eczema and an underlying cancer of the breast. The nipple is inflamed because of the presence of Paget's cells. These large irregular cells are themselves…
Pagetic

Pertaining to Paget disease, a chronic disorder that typically results in enlarged, deformed bones due to excessive breakdown and formation of bone tissue that can cause bones to weaken and may result in bone pain…
Pagon syndrome

Congenital anemia with spinocerebellar ataxia (wobbliness). The anemia is characterized by sideroblasts (iron-rich ancestors of red blood cells). The spinocerebellar ataxia becomes evident by 1 year of age. The syndrome…
PAH

Polycyclic aromatic hydrocarbon
Pain

An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a…
Pain management

Pain management: The process of providing medical care that alleviates or reduces pain. Pain management is an extremely important part of health care, as patients forced to remain in severe pain often become agitated…
Pain unit

A measurement of the intensity of pain. See also: Dol
Pain, abdominal

See: Abdominal pain
Pain, ankle

Pain felt in the low or upper back. There are many causes of back pain. Pain in the low back can relate to the bony lumbar spine, discs between the vertebrae, ligaments around the spine and discs, spinal cord and…
Pain, back

Pain felt in the low or upper back. There are many causes of back pain. Pain in the low back can relate to the bony lumbar spine, discs between the vertebrae, ligaments around the spine and discs, spinal cord and…
Pain, belly

Pain in the abdomen. See: Abdominal pain
Pain, breast

Pain in the breast or mammary gland, known medically as mastalgia. From the Greek masto-, breast + algos, pain
Pain, chest

See: Chest pain
Pain, elbow

Elbow pain is most often the result of tendinitis, which can affect the inner or outer elbow. Treatment includes ice, rest, and medication for inflammation. Elbow pain has many other causes including arthritis and…
Pain, false labor

The pain associated with intermittent non-productive muscular contractions of the womb (uterus) during pregnancy, most commonly in the last two months before full term. These contractions are non-productive in the sense…
Pain, knee

Causes of knee pain include injury, degeneration, arthritis, infrequently infection and rarely bone tumors.