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:
Search for 'O'
| Phrase | Definition |
|---|---|
| obesity | Having too much body fat. A weight more than 20% above the normal range. |
| obsession | An ongoing preoccupation with an idea. |
| obsessive-compulsive | Marked by a need to repeatedly perform certain behaviors or rituals. |
| obstetrics | The branch of medicine that deals with the care and treatment of women during pregnancy and childbirth. |
| occiput | The back of the head. |
| occult | Hidden from view. |
| occupational illness | Any illness caused or aggravated by a person's job. |
| occupational therapy | Teaching useful skills to sick or handicapped people to promote rehabilitation and healing. |
| ocular | Having to do with the eye. |
| odontalgia | Toothache. |
| olecranon | The projection of the ulna (the larger of the two bones in the forearm) at the elbow. |
| olfactory | Having to do with the sense of smell. |
| oligomenorrhea | Light menstrual flow. |
| oligospermia | A low number of sperm in the semen. |
| oliguria | A condition characterized by an abnormally small output of urine. |
| oncology | The study of tumors. |
| oophorectomy | The surgical removal of an ovary. |
| ophthalmology | The branch of medicine that pertains to the eye and its diseases. |
| optic neuritis | Inflammation of the optic nerve, which connects the eye to the brain. Symptoms include pain with eye movement, blurred vision and sometimes temporary blindness. |
| optical | Having to do with vision. |
| optometry | The practice of eye and vision care. |
| orbit | The bony cavity containing the eyeball. Eye socket. |
| orchiectomy | The surgical removal of one or both testicles. Also called castration. |
| organ | A structural unit of an animal or plant that serves a specific function. |
| organic | Having to do with substances derived from living organisms. |
| orgasm | Sexual climax. |
| orifice | The entrance or outlet of a body cavity. |
| oropharynx | The part of the pharynx behind the mouth and tongue. |
| orthodontics | The branch of dentistry that deals with the correction of irregularities of the teeth and related facial problems. |
| orthopedics | The branch of medicine that deals with the treatment of deformities, diseases and injuries of the bones, joints and muscles. |
| orthopnea | Difficulty breathing when lying flat. |
| oscillation | A back-and-forth motion; vibration. |
| Osgood-Schlatter disease | Inflammation of the bone and cartilage of the shin bone, just below the knee. |
| ossicle | A small bone. |
| osteoarthritis | A slowly progressive form of arthritis, usually found in older people. Characterized by deterioration of bone cartilage. |
| osteoma | A bony tumor. |
| osteomalacia | Softening of the bones resulting from deficient bone calcium. |
| osteomyelitis | Infection of a bone. |
| osteopathy | A system of therapy emphasizing primary medical care and the importance of body mechanics and manipulation to correct abnormalities. |
| osteoporosis | A bone disorder characterized by a reduction in bone density, chiefly found in women who have passed menopause and the elderly. |
| ostomy | A procedure done to make a passageway for waste. A colostomy is an example. |
| otic | Having to do with the ear. |
| otitis | Inflammation of the ear. Otitis externa (inflammation of the ear canal) is also called swimmer's ear, while otitis media is a middle-ear infection. |
| ovary | The female sex gland that contains ova, or eggs. |
| ovulation | The process in which an ovum is released from the ovary. |
| ovum | Egg; the female reproductive element. |
| oximeter | A device for determining the oxygen saturation level of the blood. |
| oxygen | A chemical element essential for sustaining life. |
| oxytocin | A pituitary hormone that encourages the pregnant uterus to contract and is sometimes used to induce labor. It also encourages milk to be expressed during breastfeeding. |
