Medical Dictionary: F

facet joints: The paired joints located on the back side of each vertebra, connecting its posterior elements to those of the vertebrae above and below; these can be a source of back pain.

false negative: Test results that incorrectly indicate that the tested disease or substance is not present.

familial combined hyperlipidemia: An inherited disorder in which the liver overproduces VLDL, causing high levels of cholesterol or triglycerides, or both.

familial hypercholesterolemia: An inherited disorder in which the liver cannot properly remove LDL particles from the blood, causing a very high cholesterol level.

fasting lipid profile: A laboratory test to determine the relative levels of HDL, LDL, and total cholesterol in the blood. Also referred to as a lipoprotein analysis, full lipid profile, or cholesterol profile.

fasting plasma glucose test: A blood test that determines the amount of glucose in the blood after an overnight fast of at least eight hours; a measure at or above 126 mg/dL indicates diabetes.

fat: One of the three major nutrients (along with carbohydrates and proteins). Fat is found in both animal and plant foods; however, fats from different sources have differing chemical compositions and health effects.

fatigue: A decrease over time in the ability to perform a physical or mental task. It includes muscle fatigue as well as central fatigue, which originates in the central nervous system and influences the perception of fatigue.

fatty acids: The primary building blocks of lipids.

fecal impaction: An accumulation of hardened stool in the intestine and rectum that makes evacuation impossible.

fecal occult blood test (FOBT): A colorectal cancer screening test, performed at home over a period of three days, that looks for blood in the stool.

femur: Thighbone.

fiber: An indigestible substance found in plant foods.

fibrin: A stringy protein that is the principal component of a blood clot.

fibrinogen: A chemical that is part of the blood-clotting process.

fibroadenoma: A benign, fibrous tumor commonly found in the breast.

fibroblasts: Cells in the skin that secrete collagen.

fibromyalgia: A disorder characterized by pain and tenderness in muscles and joints, as well as by fatigue. Similar in many respects to chronic fatigue syndrome.

fibula: The smaller bone of the calf, located in the back.

fixed joint: Fibrous tissue connecting the plates of the skull.

flaccid: Soft, not erect.

flat feet: A condition in which the arch is flat all the time (rigid flat feet) or flattens when bearing weight (flexible flat feet).

flight-or-fight response: Physiological changes, such as quickened breathing and heartbeat, brought on by stress hormones released in response to a real or perceived threat to one’s safety or ability to cope. Also referred to as the stress response.

fluorescein angiography: A diagnostic test that photographs blood vessels in the retina after the intravenous injection of a special dye.

foam cells: Lipid-laden cells, named for their foamy appearance under the microscope, which contribute to the formation of atherosclerotic plaque.

focus words: Words or phrases that enhance your sense of peace, relaxation, and connection while you practice deep breathing and other techniques that elicit the relaxation response.

follicle: A spherical group of cells that surrounds an egg before its release from the ovary.

follicle-stimulating hormone (FSH): A hormone secreted by the pituitary gland that stimulates the development of follicles in the ovaries.

food allergies: Conditions that result from the immune system’s response to certain proteins found in foods.

forehead lift: Surgical removal of loose skin between the brow and the hairline to reduce horizontal forehead lines and frown lines between the eyes and to correct drooping brows.

fovea: A pit-like depression in the middle of the macula.

fracture: A broken bone.

free fragment: A displaced portion of an intervertebral disk that has become detached from the central portion of the disk.

free radicals: Unstable molecules that can alter DNA, oxidize harmful LDL cholesterol, and damage cells and tissues throughout the body by stealing electrons. Free radicals are implicated in aging, cataracts, cancer, and heart disease, among other ills.

frequency: A type of urinary incontinence in which a person routinely needs to urinate more than eight times during the day or more than twice at night.

frequency: The pitch of a sound measured by the speed at which sound waves vibrate.

functional gastrointestinal disorders: Gut ailments whose symptoms cannot be linked to any infection or structural abnormality.

functional incontinence: Incontinence caused by problems (other than gastrointestinal conditions) that make it difficult to reach a toilet in time.

fungus: A simple, plantlike organism that can infect such tissues as skin and nails; common fungal foot infections include athlete’s foot and toenail fungus.