Glossary: O
- obesity
overweight by 30 percent of the ideal body weight.
- obsessive-compulsive disorder (OCD)
an anxiety disorder in which a person has an unreasonable thought, fear, or worry that he or she tries to manage through ritualized activity to reduce the anxiety. Frequently occurring disturbing thoughts or images are called obsessions, and the rituals performed to try to prevent or dispel them are called compulsions.
- Obstetrician/Gynecologist (OB/GYN)
Physicians who specialize in general women's medical care, diagnosis and treatment of disorders of the female reproductive system, and care of pregnant women.
- obstruction
blockage that prevents the flow of liquids or solids.
- occluded artery
an artery that is narrowed by plaque that impedes blood flow.
- occult
disease or symptoms that are not readily detectable by physical examination or laboratory tests.
- occult bleeding
blood in stool that is not visible to the naked eye.
- ocular hypertension
high (greater than 21 mm Hg) intraocular pressure.
- odorant
substance that stimulates the sense of smell.
- olfaction
the act of smelling.
- olfactometer
device for estimating the intensity of the sense of smell.
- oligomenorrhea
infrequent or light menstrual cycles.
- oma/"-oma"
a suffix meaning "tumor" or "lump."
- on-off effect, on-off phenomena
a change in the patient's condition, with sometimes rapid fluctuations between uncontrolled movements and normal movement, usually occurring after long-term use of levodopa and probably caused by changes in the ability to respond to this drug.
- oncogenes
genes that promote normal cell division.
- oncologist
physician who specializes in treating cancer.
- oophorectomy
surgery to remove one or both ovaries.
- oophoritis
inflammation of the ovary.
- open heart surgery
surgery that involves opening the chest and heart while a heart-lung machine performs for the heart.
- open surgery
cutting the skin and tissues during surgery to expose a full view of the structures and organs involved in the procedure.
- ophthalmoscopy
examination of the internal structure of the eye.
- optic nerve
a bundle of more than 1 million nerve fibers that connects the retina with the brain. The optic nerve is responsible for interpreting the impulses it receives into images.
- optional surgery
an operation the patient chooses to have done, which may not be essential to continuation or quality of life. (See also elective surgery.)
- oral and maxillofacial surgeon
orthopaedic facial surgeon who is responsible for treating a wide variety of dental problems - including the removal of impacted teeth and reconstructive facial surgery.
- oral cancer
a cancer found in the oral cavity (mouth), on the lip, and the
- oral dissolution therapy
method of dissolving cholesterol gallstones.
- orchiectomy (Also called castration.)
the surgical removal of the testicles.
- orchitis
inflammation of the testicle.
- oropharynx
the part of the throat at the back of the mouth.
- orthodontics
orthodontics is the dental specialty that focuses on the development, prevention, and correction of irregularities of the teeth, bite, and jaws.
- orthokeratology
the use of contact lenses to change the shape of the cornea in order to correct refractive error.
- orthopaedic surgeon (Also called an orthopaedist.)
a physician who diagnoses, treats, manages the rehabilitation process, and provides prevention protocols for patients who suffer from injury or disease in any of the components of the musculoskeletal system.
- orthopaedic surgery (Also called orthopaedics.)
the medical specialty devoted to the diagnosis, treatment, rehabilitation, and prevention of injuries and diseases of the body's musculoskeletal system.
- orthosis
a brace or splint used to strengthen or stabilize part of the body, usually an arm or leg.
- orthostatic hypotension
a large decrease in blood pressure upon standing; may result in fainting.
- osteitis pubis
an inflammation of the pubic symphysis, the bone to which the two hip bones connect in front of the body.
- osteoarthritis
a condition caused by wear and tear that causes inflammation of the joint, causing swelling, pain, and stiffness.
- osteoblast
cell found in bone; its function is to form the tissue and minerals that give bone its strength.
- osteoclast
very large cell formed in bone marrow; its function is to absorb and remove unwanted tissue.
- osteocyte
cell found within the bone; its function is to help maintain bone as living tissue.
- osteophyte
outgrowth of bone.
- osteoporosis
disorder in which bones thin and become brittle and more prone to fracture; most common in women after menopause due to estrogen deficiency.
- ostomy
operation that makes it possible for stool to leave the body through an opening made in the abdomen; necessary when part or all of the intestines are removed. Colostomy and ileostomy are types of ostomy.
- otitis externa
inflammation of the outer part of the ear extending to the auditory canal.
- otitis media
inflammation of the middle ear caused by infection.
- otoacoustic emissions
low-intensity sounds produced by the inner ear that can be quickly measured with a sensitive microphone placed in the ear canal.
- otolaryngologist
physician/surgeon who specializes in diseases of the ears, nose, throat, and head and neck.
- otologist
physician/surgeon who specializes in diseases of the ear.
- otoplasty (Also called ear surgery.)
a type of cosmetic plastic surgery procedure aimed at setting prominent ears closer to the head, or reducing the size of larger ears.
- otosclerosis
abnormal growth of bone in the inner ear, which prevents structures within the ear from working properly, resulting in a gradual loss of hearing.
- otoscope
a lighted instrument that allows the physician to see inside the ear.
- ototoxic drugs
drugs that can damage the hearing and balance organs located in the inner ear.
- outer ear
external portion of the ear, consisting of the pinna, or auricle, and the ear canal.
- outpatient surgery
surgery which allows the patient to go home the same day.
- ovaries
pair of small glands, located on either side of the uterus, in which egg cells develop and are stored and the female sex hormones estrogen and progesterone are produced.
- ovary
one of a pair of almond-shaped glands situated on either side of the uterus. Egg cells develop in the ovaries.
- overflow incontinence
leakage of urine that occurs when the quantity of urine produced exceeds the bladder's capacity to hold it.
- overuse conditions
injuries due to minor trauma involving soft-tissue injuries
- ovulation
release of a mature egg from an ovary.
- ovum
a mature egg cell released during ovulation from an ovary.
- oxytocin
hormone produced by the pituitary gland that stimulates contractions of the uterus during labor and release of milk during breast-feeding.
