Glossary

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Fabry's disease is an inherited condition in which an enzyme deficiency prevents the body from breaking down molecules known as glycosphingolipids. These molecules then accumulate in the kidneys, heart, and nerves and throughout the body, eventually causing serious symptoms.

The disease affects males more severely than females. In males, Fabry's disease may cause heart and kidney problems, clouding of the cornea and lens of the eye, lesions on the skin and in the mouth, decreased ability to sweat, and pain in the hands and feet. Females may not show any symptoms or may have impaired heart function.

Fabry's disease is treated with medicines that replace the missing enzyme. This medicine helps the body break down glycosphingolipids and helps prevent complications. The medicine slows the progress of Fabry's disease.

Last Revised: July 24, 2012

Author: Healthwise Staff

Medical Review: Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & Robert A. Kloner, MD, PhD - Cardiology

A false-negative test result is one that does not detect what is being tested even though it is present. A false-negative test result may thus suggest that a person does not have a disease or condition being tested for when in fact he or she does.

For example, a false-negative pregnancy test result would be one that does not detect the substance (human chorionic gonadotropin) that would confirm pregnancy, when in reality the woman is pregnant.

Last Revised: May 6, 2011

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & Thomas M. Bailey, MD - Family Medicine

A false-positive test result is one that appears to detect a disease or condition when in fact it is not present. A false-positive test result may thus suggest that a person has the disease or condition when he or she does not.

For example, a false-positive pregnancy test result would be one that appears to detect the substance (human chorionic gonadotropin) that would confirm pregnancy, when in reality the woman is not pregnant.

Last Revised: May 6, 2011

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & Thomas M. Bailey, MD - Family Medicine

Having a family history means that a person has one or more blood relatives with a certain health problem. A doctor can look at a person's family history to get some idea of the person's risk for that health problem.

Blood relatives include relatives who are alive and those who have died. They may be:

  • First-degree relatives (parents, sisters, brothers, and children).
  • Second-degree relatives (aunts, uncles, nieces, nephews, and grandparents).
  • Third-degree relatives (first cousins).

Some family histories are stronger than others. How strong a family history is depends on:

  • How closely related a person is to the relatives with the health problem.
  • How many relatives had or have the health problem.

Last Revised: April 6, 2012

Author: Healthwise Staff

Medical Review: Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & Robert A. Kloner, MD, PhD - Cardiology

Family medicine physicians, also called family practice physicians, are medical doctors who specialize in the total health care of the individual and the family. After four years of medical school, they complete an additional three-year residency program.

Family medicine physicians can diagnose and treat a variety of health conditions and diseases for males and females of all ages. They may further specialize in another area of medicine, such as the care of older adults (geriatric medicine) or people who have sports injuries (sports medicine).

Family medicine physicians can be board-certified by the Board of Family Practice, which is recognized by the American Board of Medical Specialties.

Last Revised: August 17, 2012

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & E. Gregory Thompson, MD - Internal Medicine

A fasting blood test is a blood sample taken from a person who has not eaten for 8 to 12 hours. Usually, the blood sample is taken early in the morning.

Examples of blood tests that may be done after a period of fasting include fasting blood sugar (fasting plasma glucose) and lipid profile (cholesterol and triglycerides).

Last Revised: September 20, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Jennifer Hone, MD - Endocrinology, Diabetes and Metabolism

Fatigue is a feeling of tiredness or exhaustion or a need to rest because of lack of energy or strength.

Fatigue may result from overwork, poor sleep, worry, boredom, or lack of exercise. It is a symptom that may be caused by illness, medicine, or medical treatment such as chemotherapy. Anxiety or depression can also cause fatigue.

Last Revised: January 7, 2013

Author: Healthwise Staff

Medical Review: William H. Blahd, Jr., MD, FACEP - Emergency Medicine & David Messenger, MD

Fetal ultrasound uses reflected sound waves to provide an image of the fetus and placenta. Fetal ultrasound is the safest way to obtain information about the fetus, such as its size, position, age, and condition.

During a fetal ultrasound, a small handheld instrument called a transducer is used to direct sound waves through the pregnant woman's abdomen. A computer analyzes the sound waves that are reflected back from the fetus and other structures in the uterus and converts them into an image. Fetal ultrasound can be done by moving the transducer across the woman's abdomen (transabdominal) or by inserting the transducer in her vagina (transvaginal). After about the 11th week of pregnancy, almost all fetal ultrasounds are done using the transabdominal method.

Last Revised: June 18, 2012

Author: Healthwise Staff

Medical Review: Sarah Marshall, MD - Family Medicine & William Gilbert, MD - Maternal and Fetal Medicine

A fetus is the growing baby in the womb (uterus) from 10 completed weeks after a pregnant woman's last menstrual period until birth.

Last Revised: July 23, 2012

Author: Healthwise Staff

Medical Review: Sarah Marshall, MD - Family Medicine & Kirtly Jones, MD - Obstetrics and Gynecology

Dietary fiber is the part of plant foods that the body cannot digest. Eating foods with fiber helps to keep the digestive tract healthy, stabilize blood sugar levels, and control cholesterol levels.

The recommended daily intake of fiber is 25 grams for women and 38 grams for men.

Fiber in the diet is classified as either soluble or insoluble.

  • Soluble fiber. As part of a low-fat, low-cholesterol diet, soluble fiber has been shown to help lower blood cholesterol. Foods high in soluble fiber include oat bran, oatmeal, dry beans and peas, rice bran, barley, citrus fruits, strawberries, and apple pulp (the solids left after making apple juice).
  • Insoluble fiber. Insoluble fiber does not lower blood cholesterol, but it is important in keeping the bowels healthy and preventing constipation and diverticular disease. Foods high in insoluble fiber include whole wheat breads, whole-grain cereals, and whole bran. Other examples are cabbage, beets, carrots, brussels sprouts, turnips, cauliflower, and apple skin.

Bran is widely known as a good source of fiber. But many commercially made bran products, such as muffins and waffles, actually contain very little bran, and they are often high in saturated and total fat. Check the labels for the actual fiber content.

Last Revised: January 25, 2013

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Rhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator

Fibromyalgia is a condition that causes widespread pain in the muscles and soft tissues. People who have it feel pain, tenderness, or both even when there is no injury or inflammation.

Depression, stress, and sleep problems are common in people who have fibromyalgia. These problems may make fibromyalgia symptoms worse.

Last Revised: October 9, 2012

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & Karin M. Lindholm, DO - Neurology

Flashes of light are "sparks" that you may see when you move your head. They can happen when the vitreous gel in your eye pulls or tugs (causes traction) on the retina. This creates nerve impulses that appear as flashes of light.

The flashes are easier to see when your eyes are closed or you are looking at a dark area. They may come and go.

Flashes of light are often harmless, but they can be a sign of a retinal problem and should be checked by a doctor right away.

Last Revised: May 11, 2012

Author: Healthwise Staff

Medical Review: Adam Husney, MD - Family Medicine & Carol L. Karp, MD - Ophthalmology

Floaters are shadows or dark objects that "float" across your field of vision. Floaters may appear as dark specks, strings, or cobwebs that float through the eye.

Many people begin to see floaters as they get older and their eyes age. If floaters have been present before, or if they occur with a diagnosed migraine headache, this condition is usually not serious. They are usually caused by tiny bits of solid tissue that collect in the thick fluid that fills the center of the eye (vitreous gel), blocking light to the retina.

Sudden development of floaters or black dots may mean that a retinal blood vessel has broken and is bleeding into the middle of the eye. This condition, called vitreous hemorrhage, results from the vitreous gel tugging on the retina. It may also be a sign of a serious retinal tear, which requires immediate medical attention.

Last Revised: August 7, 2011

Author: Healthwise Staff

Medical Review: Adam Husney, MD, MD - Family Medicine & Carol L. Karp, MD - Ophthalmology

Fluoroscopy is a test that uses a steady beam of X-ray to look at parts of the body and movement within the body, such as blood moving through a blood vessel. Fluoroscopy also can be used to help find a foreign object in the body, position a needle for a medical procedure, or realign a broken bone. A dye (contrast material) that shows up on fluoroscopy can be put in a vein (IV) or swallowed so vessels or organs show up clearly.

Fluoroscopy usually is done during other diagnostic procedures. For example, fluoroscopy is done during cardiac catheterization to look at the coronary arteries and the flow of blood through them. Fluoroscopy also may be used to look at the urinary tract or during a hysterosalpingogram to look at a woman's reproductive organs.

Fluoroscopy uses more radiation than standard X-rays.

Last Revised: June 29, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Avery L. Seifert, MD - Urology

Folic acid, one of the B vitamins, is important for the normal development of an unborn child (fetus). Folic acid and its closely related compounds, folates, are needed for the production of red and white blood cells and platelets, the formation of genetic material (DNA) in cells, and growth.

Only a small amount of folic acid is stored in the body. So to avoid a deficiency, you must get folic acid regularly from the foods in your diet. Folic acid is found in foods such as liver, kidney, yeast, fruits (bananas, oranges), leafy vegetables (spinach), eggs, whole wheat bread, lima beans, and milk.

Taking supplements of folic acid before and during pregnancy can reduce the chance of having a baby with birth defects, such as spina bifida.

Last Revised: December 18, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Joseph O'Donnell, MD - Hematology, Oncology

Folic acid deficiency anemia results from lower-than-normal levels of folic acid in the body. It causes symptoms such as weakness, fatigue, and lightheadedness.

Causes of folic acid deficiency anemia include:

  • Not getting enough folic acid in the diet.
  • An increased need for folic acid, as can happen during pregnancy or with certain diseases, such as sickle cell disease.
  • Drinking too much alcohol.
  • Certain medicines.
  • Artificial cleansing of the blood (hemodialysis), as is done to treat kidney disease.

Folic acid deficiency anemia is treated by increasing a person's intake of folic acid (folate).

Last Revised: December 18, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Joseph O'Donnell, MD - Hematology, Oncology

Follicle-stimulating hormone (FSH) helps control a woman's menstrual cycle and egg production and also a man's sperm production. FSH is produced by the pituitary gland.

Women's FSH levels normally vary throughout the menstrual cycle and are highest just before release of an egg (ovulation). Men's FSH levels normally stay at a constant level. An abnormally high or low level of FSH is often a sign of an inability to produce eggs or sperm.

Last Revised: December 7, 2011

Author: Healthwise Staff

Medical Review: Sarah Marshall, MD - Family Medicine & Femi Olatunbosun, MB, FRCSC - Obstetrics and Gynecology

A fungus is an organism that can grow on living and nonliving things. Fungi (the plural of fungus) include many types of organisms including yeasts, mold, and mushrooms. Fungi that cause problems for people include yeasts and molds and other types of fungi.

In some situations, fungi can infect and damage tissue, such as skin, hair, or nails. Fungi also may be involved in infections throughout the body, such as in the central nervous system or the bloodstream.

Last Revised: June 27, 2012

Author: Healthwise Staff

Medical Review: Patrice Burgess, MD - Family Medicine & E. Gregory Thompson, MD - Internal Medicine