Glossary

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

O

Obesity - a condition in which there is an excess of body fat; used to describe those who weigh at least 20 percent more than the maximum amount considered normal for their age, sex, and height

Obsessive-compulsive disorder - a mental disorder in which a person is obsessed with certain thoughts, leading them to repeatedly perform specific acts; for example, constantly washing the hands out of fear of germs and dirt

Occult blood - blood in the feces that can be detected only by chemical tests

Oligohydramnios - an unusually small amount of amniotic fluid surrounding the fetus in the uterus, which can lead to complications with the pregnancy

Oligospermia - a low level of sperm in the semen; one of the main causes of infertility in men

Oncogenes - genes that, when altered by environmental factors or viruses, can cause abnormal cell growth

Oocyte - an egg cell that has not developed completely

Oophorectomy - the surgical removal of one or both ovaries; used to treat the growth of ovarian cysts or tumors

Optic nerves - the pair of nerves that carry visual information from the retina to the brain

Optic neuritis - inflammation of the optic nerve, often causing a partial loss of vision

Oral contraceptives - drugs taken in pill form to prevent pregnancy; contain synthetic progesterone and estrogen hormones

Orchiectomy - the surgical removal of one or both of the testicles

Orchiopexy - an operation to correct an undescended testicle

Orchitis - inflammation of a testicle, which can be caused by infection with the mumps virus

Organ donation - an agreement to allow one or more organs to be removed and transplanted into someone else

Organism - any single, functioning form of life

Orgasm - involuntary contraction of genital muscles experienced at the peak of sexual excitement

Orthopnea - breathing difficulty experienced while lying flat; can be a symptom of heart failure or asthma

Ossification - the formation and maintenance of bone

Osteitis - inflammation of bone

Osteitis deformans - another name for Paget's disease

Osteoblast - a cell that forms bone

Osteoclast - a cell that breaks down unwanted bone tissue; also refers to a device for fracturing a bone to correct a deformity

Osteodystrophy - defective bone formation

Osteogenesis imperfecta - a genetic disorder in which bones are abnormally fragile, leading to multiple breaks and deformity

Osteolysis - the softening and destruction of bone

Osteomalacia - the loss of minerals and softening of bones because of a lack of vitamin D; called rickets in children

Osteomyelitis - the inflammation of bones and bone marrow because of an infection, usually caused by bacteria

Osteopetrosis - a rare hereditary disorder in which bones become harder and more dense, causing them to break more easily

Osteophyte - an outgrowth of bone near a joint

Osteoporosis - a condition in which bones become less dense, more brittle, and fracture easily

Osteosarcoma - a cancerous bone tumor

OTC remedy - see Over-the-counter remedy

Outpatient treatment - medical attention that does not include an overnight stay at a hospital

Ovaries - two almond-shaped glands located at the opening of the fallopian tubes on both sides of the uterus; produce eggs and the sex hormones estrogen and progesterone

Overdose - an excessively large dose of a drug, which can lead to coma and death

Over-the-counter remedy - a medication that can be purchased without a physician's prescription

Ovulation - the development and release of the egg from the ovary, which usually occurs halfway through a woman's menstrual cycle

Ovum - another term for an egg cell

Oximetry - determination of the amount of oxygen in the blood by measuring the amount of light transmitted through an area of skin

Oxygen - a gas that is colorless, odorless, and tasteless; essential to almost all forms of life

Oxytocin - a hormone produced in the pituitary gland that causes contraction of the uterus during childbirth and stimulation of milk flow during breast-feeding

Ozone - a poisonous form of oxygen that is present in the earth's upper atmosphere, where it helps to screen the earth from damaging ultraviolet rays

O

Related Information

  • Do we take your insurance?
    Want to make an appointment?
    Got questions? We've got answers.     Patient Resources
  • Can't find what you're looking for? Contact Us