Dictionary

photophobia Sunglasses may also help.

photorefractive keratectomy A kind of laser eye surgery that is designed to correct vision by changing the shape of the cornea, potentially eliminating or reducing the need for glasses or contact lenses. Abbreviated PRK. A laser is used to remove the outer layer of the cornea and flatten the cornea. PRK is done in a…

photosensitivity Oversensitivity of skin to light. Photosensitivity can be a side effect of medications or result from diseases, such as lupus. Treatment depends on the severity of the reaction and the cause. Photosensitivity can be prevented by avoiding skin exposure to ultraviolet light.

phototherapy Treatment with light. For example, a newborn with jaundice may be put under special lights to help reduce the amount of bilirubin pigment in the skin.

phototoxicity An exaggerated response to ultraviolet radiation (sunlight) characterized by rapidly developing or severe sunburn. Phototoxicity may be associated with certain medications, including the antibiotic tetracycline.

phrenology The study of variations in the size, shape, and proportion of the cranium. Phrenology was a pseudoscience of the 18th and 19th centuries, based on the belief that a person’s character could be learned by looking with care at the shape of the person’s head and noting each and every bump and depression in…

PHS Public Health Service. See United States Public Health Service.

physiatrist A physician who specializes in physical medicine and rehabilitation. Physiatrists specialize in restoring optimal function to people with injuries to the muscles, bones, tissues, or nervous system, such as stroke victims.

physical map A map of the locations of identifiable landmarks on chromosomes. Physical distance between landmarks is measured in base pairs. The physical map differs from the genetic map, which is based purely on genetic linkage data. In the human genome, the lowest-resolution physical map is the banding patterns of the 24 different chromosomes. The…

physical therapist A person who is trained and certified by a state or accrediting body to design and implement physical therapy programs. Abbreviated PT. PTs may work in hospitals or clinics, in schools that provide assistance to special education students, or as independent practitioners.

physical therapy A branch of rehabilitative health that uses specially designed exercises and equipment to help patients regain or improve their physical abilities. Abbreviated PT. PT is appropriate for many types of patients, from infants born with musculoskeletal birth defects, to adults suffering from sciatica or the after effects of injury or surgery, to elderly…

physician A person who is trained in the art of healing. In the UK, a physician is a specialist in internal or general medicine, whereas in the US a physician is any doctor of medicine. The term generally refers to a person who has earned a Doctor of Medicine (MD), Doctor of Osteopathy (DO), or…