Find over 200 print-friendly fact sheets about heart disease and related health topics.
Find definitions for thousands of medical terms, treatments, and tests -- even health-related abbreviations, prefixes, and suffixes.
A Valsalva maneuver is an effort to exhale without letting air
escape through the nose or mouth. People often use a Valsalva maneuver during
some common activities, such as straining to have a bowel movement or blowing a
A Valsalva maneuver is not normally harmful. But it may cause
irregular heart rhythms in some people who have certain types of heart
A person may be asked to do a Valsalva maneuver during certain
medical tests or exams. During the test, a person is asked to try to breathe
using the stomach muscles and diaphragm but not let any air out through the
nose or mouth.
August 9, 2012
Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & John M. Miller, MD, FACC - Cardiology, Electrophysiology
Varicose veins are twisted, enlarged veins near the surface of the skin. They're most common in the legs and ankles. They usually aren't serious.
October 9, 2012
E. Gregory Thompson, MD - Internal Medicine & David A. Szalay, MD - Vascular Surgery
Vascular (or multi-infarct) dementia refers to a decline in a
person's mental abilities that results from a series of strokes. A stroke
occurs when blood flow to part of the brain is blocked, cutting off the blood
supply to the brain.
Vascular dementia often progresses step by step, with declines in
memory and mental functions occurring each time another stroke occurs. The
specific symptoms a person has depend on which area of the brain the strokes
have affected. Not all strokes cause symptoms.
Vascular dementia is often associated with hardening of the
arteries (atherosclerosis) caused by high cholesterol, high blood pressure, or
diabetes. A person can reduce the risk of future strokes by controlling high
blood pressure, reducing cholesterol, quitting smoking, and taking aspirin and
other drugs used to treat these conditions.
June 23, 2011
Anne C. Poinier, MD - Internal Medicine & Peter J. Whitehouse, MD - Neurology
Vascular surgeons are medical doctors who specialize in the
diagnosis, medical management, and surgical treatment of diseases of the blood
vessels (vascular disease).
surgeons can be board-certified through the Board of Surgery, which is
recognized by the American Board of Medical Specialties.
August 17, 2012
Anne C. Poinier, MD - Internal Medicine & E. Gregory Thompson, MD - Internal Medicine
A vena cava filter is an umbrella-shaped barrier device that is
inserted into the large vein that returns blood to the heart from the abdomen
and legs (inferior vena cava). This filter helps prevent blood clots that form
in the deep veins of the lower limbs from traveling to the lungs and heart
where they may block blood flow.
Vena cava filters are inserted into the vena cava using a catheter
inserted through a vein in the neck or groin.
January 10, 2013
E. Gregory Thompson, MD - Internal Medicine & Jeffrey S. Ginsberg, MD - Hematology
Venous insufficiency occurs when the veins in the legs do not
return blood to the heart and upper body normally. Causes include long-term
high blood pressure inside leg veins and blood clots in leg veins (deep vein
thrombosis or phlebitis).
The veins in the body have valves that prevent blood from flowing
the wrong way. These valves keep blood flowing toward the heart. Venous
insufficiency means that the valves in the veins have become damaged, allowing
blood to flow backward and pool in the leg veins. This results in swelling of
the legs (lower extremities) and may cause varicose veins.
Symptoms of venous insufficiency include swollen ankles, tight
calves, and an aching or heaviness in the legs.
Self-care measures may relieve symptoms. These measures include
exercising regularly, wearing compression stockings, avoiding long periods of
standing, and elevating the legs.
August 31, 2011
E. Gregory Thompson, MD - Internal Medicine & Margaret Doucette, DO - Physical Medicine and Rehabilitation, Wound Care, Hyperbaric Medicine
A venous skin ulcer is a shallow wound caused by venous
insufficiency, a condition in which the valves in the blood vessels are damaged
and allow some blood to back up in the veins. The slowed circulation causes
fluid to seep out of the overfilled veins into surrounding tissues, causing
tissue breakdown and ulcers.
Venous skin ulcers, also called stasis leg ulcers, typically
develop on either side of the lower leg, above the ankle and below the
The first sign of a skin ulcer is an affected area of skin that
turns dark red or purple. It may also become thickened and dry and itchy.
Without treatment, an open wound (ulcer) may form. Venous skin ulcers often
weep clear fluid and are covered with yellowish film.
The most effective treatment for venous skin ulcers is frequent
elevation of the legs above the level of the heart and use of compression
stockings during waking hours.
The ventricles are the two lower chambers of the heart, one on the
right and one on the left. The ventricles receive blood from the heart's upper
chambers (atria) and pump it to the rest of the body.
The right ventricle pumps blood to the lungs, and the left
ventricle pumps blood to the rest of the body.
April 4, 2011
E. Gregory Thompson, MD - Internal Medicine & John M. Miller, MD, FACC - Cardiology, Electrophysiology
Ventricular septal defect (VSD), the most common heart problem that
develops before birth (congenital), is an opening in the wall that
separates the lower chambers of the heart. Most ventricular septal defects are
small and do not cause a problem.
The opening of a ventricular septal defect can be as small as a
pinhole, or the wall between the heart chambers may be completely missing. This
defect is usually found when a baby is 1 to 4 weeks old.
A large, untreated ventricular septal defect may result in the
lower left heart chamber's inability to pump enough blood to the body and too
much blood going to the lungs. Large ventricular septal defects usually cause
heart problems and symptoms by the time a baby is 3 to 6 months old.
Treatment is not needed in cases where a ventricular septal defect
is small or closes on its own. Some children and adults need surgery or a catheter
procedure to close the defect, especially if it is large.
October 11, 2011
John Pope, MD - Pediatrics & Larry A. Latson, MD - Pediatric Cardiology
Vertigo (dizziness) is an uncomfortable feeling of motion when
there is no actual movement. The feeling of motion is commonly described as
spinning or whirling. But it also may include sensations of falling or
Vertigo can cause nausea and vomiting. You may find it difficult to walk, stand, or keep your balance.
Causes for vertigo include problems with nerves, blood flow, and the inner-ear.
Infrequent episodes of vertigo may not require treatment. If
vertigo is severe or frequent, treatment will depend on the specific
December 19, 2012
Aerobic fitness means increasing how well the body uses oxygen,
which depends on the condition of the heart, lungs, and muscles. Experts tend
to describe aerobic activity in three ways: light, moderate, and vigorous.
When people do vigorous-intensity activities, they breathe faster
and have a much faster heartbeat than at rest. To get the benefits of vigorous
activity, a person can:
The goal of aerobic fitness is to increase the amount of
oxygen that goes to the heart and muscles, which allows them to work longer.
Any activities, including many kinds of daily activities, that raise the heart
rate and keep it up for an extended period of time can improve aerobic fitness.
If the activities are done regularly and long enough, they can help improve
Experts recommend that adults try to do vigorous activity
for at least 1¼ hours a week. Or they can do moderate activity for at least 2½
hours a week. People can choose to do one or both types of activity. And it's
fine to be active in blocks of 10 minutes or more throughout the day and week.
Teens and children (starting at age 6) should do moderate to vigorous activity
at least 1 hour every day.
It's always a good idea to talk to
your doctor before starting an exercise program.
October 25, 2011
E. Gregory Thompson, MD - Internal Medicine & Heather Chambliss, PhD - Exercise Science
Vitamin B12 (cobalamin) is important in the formation of all
cells in the body, especially red blood cells and the covering of nerve cells
(myelin). The body needs myelin for nerves to function properly.
Vitamin B12 is found in animal products such as meat, shellfish,
milk, cheese, and eggs. Most people who eat meat are not likely to develop a
vitamin B12 deficiency. There is normally enough vitamin B12 stored in a
person's liver to last a year or more, even if the person does not eat any foods that
contain the vitamin during that time.
Some people have a disease that makes their bodies unable to absorb
vitamin B12. These people need either to get an injection of B12 once a month, to take
high-dose B12 pills, or to use a nasal spray containing B12.
Strict vegetarians (vegans) who do not eat meat, milk, cheese, or
eggs are at risk for vitamin B12 deficiency. They need a
vitamin supplement containing vitamin B12.
December 10, 2012
E. Gregory Thompson, MD - Internal Medicine & Joseph O'Donnell, MD - Hematology, Oncology
Vitamin B12 deficiency anemia is a blood problem that occurs when
there is not enough of this vitamin in the body. Vitamin B12 helps make red
blood cells. Without enough vitamin B12, the body does not produce enough red
blood cells, and cells throughout the body do not get the oxygen they
Vitamin B12 (also called cobalamin) is found in animal products
such as meat, eggs, and milk products. Most people get more than enough of this
vitamin from the food they eat. Vitamin B12 deficiency anemia usually occurs
when the body cannot absorb this vitamin from food. It can also occur if a
person's diet does not include enough of this vitamin.
A mild deficiency may not cause symptoms. As the anemia becomes
worse, symptoms may include weakness, fatigue, diarrhea or constipation,
numbness or tingling in the fingers and toes, poor sense of balance, thinking and memory problems, and/or
depression. If the condition is not treated right away, symptoms caused by damage to the brain and nerve cells may become
If vitamin B12 deficiency anemia is suspected, the doctor will do a
physical exam, take a medical history, and order blood tests that can help
diagnose this condition.
Vitamin B12 deficiency anemia is treated with supplements of
vitamin B12. These may be given as shots, pills, or a nasal spray. Vitamin B12
pills contain a higher dose of vitamin B12 than a regular vitamin pill. There is no need for any worry about getting too much vitamin B12, because the body passes extra vitamin B12 out in the urine. Most people need to take supplements
for the rest of their lives to keep the condition from coming back.
Vitamins are certain chemicals the body needs in small amounts to
function properly. They work in a variety of ways, mostly as "helpers"; for
example, many of the B vitamins help the body use protein, carbohydrate, and fats.
Vitamins are divided into two categories:
August 29, 2011
John Pope, MD - Pediatrics & Rhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator
Vitreous gel (also called vitreous humor) is a thick, colorless,
gel-like fluid that fills the large space in the middle of the eye, behind the
lens. It helps the eyeball maintain its shape.
August 7, 2011
Adam Husney, MD, MD - Family Medicine & Carol L. Karp, MD - Ophthalmology