Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «O»:
-
Over-the-counter (OTC) drug
Over-the-counter (OTC) drug: A drug for which a prescription is not needed....
-
Overactive bladder
Overactive bladder: A sudden involuntary contraction of the muscular wall of the bladder causing urinary urgency, an immediate unstoppable need to urinate. It is a form of urinary incontinence (the unintentional loss of urine) and affects about 1 in 11 adults, particularly older adults. Treatment ma...
-
Overbreathing
Overbreathing: See: Hyperventilation....
-
Overgrowth
Overgrowth: Just what it sounds like: excessive growth....
-
Overgrowth syndrome
Overgrowth syndrome: One in a group of disorders resulting in overgrowth, as evidenced by unusually large size at birth, excessive postnatal growth, and increased weight, increased length, and/or increased head circumference. There is an increased risk of cancer in a number of the overgrowth syndrom...
-
Overload, iron
Overload, iron: Iron overload can damage the heart, liver, gonads and other organs.
Iron overload is a particular risk for:
People with certain genetic conditions such as hemochromatosis; and
People receiving repeated blood transfusions.
According to the National Academy of Sciences, the
Recommend...
-
Overweight
Overweight: The term "overweight" is used in two different ways. In one sense it is a way of saying imprecisely that someone is heavy. The other sense of "overweight" is more precise and designates a state between normal weight and obesity.
The National Institutes of Health (NIH) now defines overwe...
-
Ovulation
Ovulation: The release of the ripe egg from the
ovary. The egg is released when the cavity surrounding it (the
follicle) breaks open in response to a hormonal signal. Ovulation
occurs around fourteen or fifteen days from the first day of the
woman's last menstrual cycle. When ovulation occurs, t...
-
Ovulatory
Ovulatory: Relating to ovulation, the release of the ovum (the egg) from the ovary....
-
Ovum
Ovum: An egg in the ovary of the female.
This egg is called the female "gamete" or sex cell. It combines with the male
gamete, called a sperm, to form a zygote. This formation process is called
"fertilization." (see sperm, zygote)....
-
Oxter
Oxter: The armpit. From the Old English oxta or ohsta. The word oxter is used in certain areas of the world (Scotland, Ireland, Northern England), reminding us that there are many local and colloquial names for parts of the human anatomy. Synonymous with axilla....
-
Oxy
Oxy: Street name for OxyContin, prescription painkiller that has become a popular and dangerous recreational drug.
OxyContin is a time-release morphine-like narcotic intended to relieve chronic pain of moderate to severe proportions. One pill of OxyContin is designed to last 12 hours.
The active...
-
Oxycodone
Oxycodone: Oxycodone is the active ingredient in OxyContin. Oxycodone is an opioid, a close relative of morphine, heroin, codeine, fentanyl, and methadone....
-
OxyContin
OxyContin: A prescription painkiller that has become a popular and dangerous recreational drug. Also called "Oxy" in the street.
OxyContin is a time-release morphine-like narcotic intended to relieve chronic pain of moderate to severe proportions. One pill of OxyContin is designed to last 12 hours....
-
Oxygen
Oxygen: A colorless, odorless and tasteless gas that makes up about 20% of the air we breathe (and at least half the weight of the entire solid crust of the earth) and which combines with most of the other elements to form oxides. Oxygen is essential to human, animal and plant life.
The chemical sym...
