Find definitions for thousands of medical terms, treatments, and tests -- even health-related abbreviations, prefixes, and suffixes.
A magnetic resonance angiogram (MRA) uses a magnetic field and
pulses of radio wave energy to make pictures of blood vessels inside the body.
It is a type of magnetic resonance image (MRI) scan. In many cases MRA can give
information that cannot be seen from an X-ray, ultrasound, or computed
tomography (CT) scan.
MRA can find problems with the blood vessels that may be causing
reduced blood flow. With MRA, both the blood flow and the condition of the
blood vessel walls can be seen. The test is often used to check the blood
vessels leading to the brain, kidneys, and legs. Information from an MRA can be
saved and stored on a computer for more study. Photographs of selected views
can also be made.
During MRA, the area of the body being studied is put inside an MRI
machine. A dye (contrast material) is often used during MRA to make blood
vessels show up more clearly.
June 13, 2012
Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & George Philippides, MD - Cardiology
Magnetic resonance imaging (MRI) is a test that uses a magnetic
field and pulses of radio wave energy to make pictures of organs and structures
inside the body.
In many cases, MRI gives different information about structures in
the body than can be seen with an X-ray, ultrasound, or computed tomography
(CT) scan. MRI also may show problems that cannot be seen with other imaging
For an MRI test, the area of the body being studied is placed
inside a special machine that has a strong magnet. In some cases, a dye
(contrast material) may be used during the MRI to show pictures of organs or
structures more clearly.
Photographs or films of certain views can also be made. Information
from an MRI can be saved and stored on a computer for more study.
MRI can be used to look for problems such as bleeding, tumors,
infection, blockage, or injury in the brain, organs and glands, blood vessels,
May 16, 2011
Kathleen Romito, MD - Family Medicine & Howard Schaff, MD - Diagnostic Radiology
Malignant high blood pressure (malignant hypertension) is
very high blood pressure that comes on suddenly and is an emergency. If not treated, it can damage the brain, heart, eyes, or
Quick-acting medicines are used to
lower blood pressure.
The cause may be unknown, or
the problem may be caused by medicine or another condition. Symptoms include numbness, blurry vision, chest pain, and confusion.
problem is also called hypertensive crisis or hypertensive
April 4, 2011
E. Gregory Thompson, MD - Internal Medicine & Robert A. Kloner, MD, PhD - Cardiology
Mania is a persistently elevated, irritable, or elated mood. Mania
occurs in some mood disorders, such as bipolar disorder. It also can result
from diseases, such as hyperthyroidism, or develop as a side effect of some
medicines, such as steroids or antidepressants.
Other characteristics of mania include:
Mania is usually treated with professional counseling and
medicines, such as mood stabilizers. If mania is caused by a reaction to a
medicine, it usually goes away when the person stops taking the medicine.
March 1, 2012
Patrice Burgess, MD - Family Medicine & Lisa S. Weinstock, MD - Psychiatry
Manual therapy (sometimes called bodywork) is a general term
for treatment performed mostly with the hands. The goals of manual therapy include relaxation, decreased pain, and
Manual therapy can include:
January 30, 2013
William H. Blahd, Jr., MD, FACEP - Emergency Medicine & Robert B. Keller, MD - Orthopedics
Marfan's syndrome is an inherited disorder that causes problems in
the connective tissues of the blood vessels, heart, and eyes, and affects the
muscles, ligaments, bones, and tendons. People with Marfan's syndrome tend to
be tall and thin with long arms, legs, fingers, and toes.
Because of problems with their connective tissues, people who have Marfan's syndrome are at risk of:
Treatment for Marfan's syndrome includes treating specific problems
related to the connective tissue disease, such as heart problems.
November 2, 2011
Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & Stephen Fort, MD, MRCP, FRCPC - Interventional Cardiology
Ménière's (say "men-YEERS") disease is a disorder of the inner
ear that affects hearing and balance. It causes sudden attacks of vertigo (a
spinning sensation), tinnitus (a loud ringing in the ears), and hearing loss
that may be temporary or permanent.
It may also cause:
The cause of Ménière's disease is not known, but it may be
related to a fluid imbalance in the inner ear.
medicines and sometimes surgery.
Avoiding caffeine, alcohol, tobacco, salt, and stress may prevent attacks of
April 12, 2012
Anne C. Poinier, MD - Internal Medicine & Barrie J. Hurwitz, MD - Neurology
A meniscus is a piece of cartilage (rubbery tissue) that acts as a
shock absorber between bones and stabilizes the joints by evenly distributing
the load across the joint area. Menisci (plural of meniscus) protect and
cushion the joint surface and bone ends.
In the knee, the crescent-shaped menisci are positioned between
the ends of the upper (femur) and lower (tibia) leg bones. The menisci protect
the knee joint surface. And they absorb the shock produced by activities such as
walking, running, and jumping.
September 10, 2012
William H. Blahd, Jr., MD, FACEP - Emergency Medicine & Patrick J. McMahon, MD - Orthopedic Surgery
A meniscus tear is damage to one of the rubbery discs that cushion your knee joint. It's usually caused by twisting your knee while your foot stays planted on the ground. It can be painful and keep your knee from working right.
Some tears will heal with rest and physical therapy. Others need to be repaired with surgery.
October 9, 2012
Menopause is the point in a woman's life when her ovaries stop producing enough hormones to keep the menstrual cycle going. It's sometimes called "the change of life." It usually happens around age 50, but every woman's body has its own timeline.
Some women go through menopause early because of cancer treatment or surgery to remove the ovaries.
Menopause is a natural part of growing older. You don't need treatment unless your symptoms bother you.
Anne C. Poinier, MD - Internal Medicine & Carla J. Herman, MD, MPH - Geriatric Medicine
Metabolic syndrome is a cluster of conditions related to the body's
metabolism. These conditions include excess body fat (particularly abdominal
obesity); elevated triglycerides, blood pressure, and blood sugar; and low HDL
cholesterol (the "good" cholesterol).
Metabolic syndrome is closely linked to insulin resistance, in
which the body cannot use insulin properly.
Metabolic syndrome increases the risk for coronary artery disease
(CAD), even beyond that caused by high LDL cholesterol alone. Weight loss and
increased physical activity can reduce the risk for metabolic syndrome.
May 22, 2012
E. Gregory Thompson, MD - Internal Medicine & Jennifer Hone, MD - Endocrinology, Diabetes and Metabolism
Metabolism refers to all of the chemical processes that take place
in the body, such as the burning of sugars (glucose) for energy and the release
of digestive enzymes to break down food. Metabolism results in growth, the
elimination of waste products (in urine and stool), healing of wounds, and
other necessary activities of the body.
Many things can affect the rate of metabolism, including exercise,
diet, temperature, and hormones.
When problems occur with any of the normal metabolic processes,
changes in the body can occur (such as diabetes or thyroid disease). Changes in
metabolism can affect the entire body.
June 20, 2012
E. Gregory Thompson, MD - Internal Medicine & David C.W. Lau, MD, PhD, FRCPC - Endocrinology
Some medical tests report results in micrograms (mcg). A microgram is
one-millionth of a gram. A gram is about 1/30 of an ounce.
May 6, 2011
Anne C. Poinier, MD - Internal Medicine & Thomas M. Bailey, MD - Family Medicine
Some medical tests report results in micrograms per liter
A microkat is a unit of measurement used in chemistry to describe
enzyme reactions. A catalyst starts or speeds up a chemical reaction. Enzymes
are proteins that act as catalysts in the body. A catalyst measures one katal
if it causes a chemical reaction at one mole per second. A liter is a measure
of volume that is a little more than a quart.
Some medical tests report results using microkats per liter
Some medical tests report results in micromoles per liter
Migraines are throbbing headaches that last from 4 to 72 hours, usually on one side of your head. They may be triggered by certain foods or smells.
They may cause nausea and vomiting. And light may make the pain worse. Some people have an aura—like seeing wavy lines or flashing lights—before the headache starts.
Although migraines are painful, they can often be treated with pain medicines and sometimes with medicines to prevent the headaches.
Anne C. Poinier, MD - Internal Medicine & Colin Chalk, MD, CM, FRCPC - Neurology
Some medical tests report results in milliequivalents per liter
Some medical tests report results in milligrams (mg). A milligram is
one-thousandth of a gram. A gram is about 1/30 of an ounce.
Some medical tests report results in milligrams (mg) per deciliter
Some medical tests report results in milligrams per liter
Some medical tests report results in milliliters (mL). A milliliter
measures fluid volume. It is equal to one-thousandth of a liter. A liter is a
little bigger than a quart. A milliliter is also called a cubic centimeter
Pressure is measured in millimeters (mm) of mercury (Hg). A special
unit that measures pressure shows how high a column of mercury rises.
Some medical tests report results in millimoles per liter
The mitral valve separates the left upper chamber (left atrium) and
left lower chamber (left ventricle) of the heart. The mitral valve is formed
from two downward-facing flaps.
When the heart pumps,
blood forces the flaps open, and blood flows from the left atrium to the left
ventricle. Between heartbeats, the flaps close tightly so that blood does not
leak backward through the valve.
November 18, 2011
Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & John A. McPherson, MD, FACC, FSCAI - Cardiology
Mitral valve prolapse (MVP) is a common condition in which the
mitral valve between the left upper chamber (left atrium) and left lower
chamber (left ventricle) of the heart does not function properly. In most
people, mitral valve prolapse does not cause any symptoms, usually does not
cause any health problems, and does not require treatment.
In mitral valve prolapse, the valve flaps bulge (prolapse) upward
into the left atrium rather than closing smoothly as the heart contracts. In
rare cases, blood may leak backward through the prolapsed valve into the
atrium. This condition is called mitral valve regurgitation.
January 23, 2013
E. Gregory Thompson, MD - Internal Medicine & Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology
Mitral valve regurgitation (MR) is the leaking or backflow of
blood through the valve between the upper left heart chamber (atrium) and the lower left heart chamber (ventricle). If serious, this condition can lead to a
backup of blood in the left atrium and the lungs, cause enlargement of and
damage to the left ventricle, and lead to heart failure.
valve regurgitation can either be ongoing (chronic) or sudden (acute). Chronic
MR develops slowly, possibly over decades, and symptoms, such as shortness of
breath, fatigue, and swelling in the feet and ankles, may never appear. Acute
MR is a medical emergency that requires urgent treatment to repair or replace
the mitral valve.
Treatment for MR includes medicines for symptoms
and eventually surgery to repair or replace the valve.
have mitral valve regurgitation may be at higher risk of heart valve infection
(endocarditis) especially if they have an artificial heart valve.
November 29, 2011
Mitral valve stenosis is a heart condition in which the mitral
valve—which regulates blood flow on the left side of the heart—fails to open as
wide as it should. Although it has no immediate effect on health, eventually
mitral valve stenosis can cause the left atrium to work harder to pump blood
through the narrowed valve, leading to heart failure and complications such as
stroke, heart rhythm problems (such as atrial fibrillation), fluid buildup in
the lungs, and blood clots.
Symptoms usually do not develop for 10
to 20 years and may take as long as 40 years to be noticed. Early symptoms, such as
shortness of breath with exertion, are often mild and hard to distinguish from
other forms of heart disease. In the later stages of mitral valve stenosis,
blood may back up into the lungs, causing symptoms such as shortness of breath,
fatigue, weakness, and pounding of the heart.
Treatment for mitral
valve stenosis depends on whether symptoms are present and how much the mitral valve has narrowed. Close monitoring is usually all that's needed
for those who have mild or no symptoms. But if symptoms and severe narrowing are
present, a doctor may recommend surgery to
repair or replace the valve.
Difficulty breathing can occur when the body's lungs or heart are
not working well.
Moderate trouble breathing means:
Severe trouble breathing means:
December 21, 2011
William H. Blahd, Jr., MD, FACEP - Emergency Medicine & David Messenger, MD
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
When people do moderate-intensity activities, they
notice a faster heartbeat. To get the benefits of moderate activity, a person
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 moderate activity
for at least 2½ hours a week. Or they can do vigorous activity for at least 1¼
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.
Moderate activity is safe for most
people, but it's always a good idea to talk to your doctor before starting an
October 25, 2011
E. Gregory Thompson, MD - Internal Medicine & Heather Chambliss, PhD - Exercise Science
Mononucleosis, or "mono," is a common illness caused by a virus. It's often seen in teens and young adults. It can cause a bad sore throat, swollen neck glands, and fever. Some people feel tired and weak for weeks or months after getting sick.
Mono usually goes away on its own, but rest and good self-care can help you feel better.
Mono is nicknamed "the kissing disease" because that's one way the virus is spread. If you have mono, don't kiss anyone or share things like drinking glasses, eating utensils, or toothbrushes.
E. Gregory Thompson, MD - Internal Medicine & W. David Colby IV, MSc, MD, FRCPC - Infectious Disease
Multiple myeloma (plasma cell neoplasm) is a rare type of cancer
that results in the uncontrolled production of one type of white blood cell
(plasma cell) in the bone marrow. The cancer cells can crowd out normal blood
cells, causing a reduction in red blood cells (anemia).
The overproduction of plasma cells causes an increase in
antibodies. The plasma cells also may cause the bone to break down. The plasma
cells can collect in the bone to make small tumors called plasmacytomas.
The most common symptoms of multiple myeloma include night sweats,
weight loss, weakness, fatigue, bone pain, pneumonia, numbness, paralysis, or
kidney failure. If the bones of the spine are involved, they may collapse. This causes spinal cord compression.
The exact cause of multiple myeloma is not known. It is slightly
more common in men than in women. And it is usually diagnosed between the ages of
40 and 70. The disease is very rare before the age of 40.
Multiple myeloma is usually treated with chemotherapy to reduce the
numbers of abnormal plasma cells, antibiotics to help fight infection, and pain
medicine. Radiation therapy may be used to treat bone masses.
December 14, 2012
E. Gregory Thompson, MD - Internal Medicine & Brian Leber, MDCM, FRCPC - Hematology
Multiple sclerosis, often called MS, is a disease that gradually destroys the protective covering of nerve cells in the brain and spinal cord. This can cause problems with muscle control and strength, vision, balance, feeling, and thinking.
MS has no cure, but medicines may help lower the number of attacks and make them less severe.
Adam Husney, MD - Family Medicine & Anne C. Poinier, MD - Internal Medicine & Barrie J. Hurwitz, MD - Neurology
Muscle fitness means having muscles that can lift heavier
objects or muscles that will work longer before becoming exhausted. Muscle
fitness improves when a person does activities that build or maintain muscles
(strength) or that increase how long a person can use his or her muscles
Activities like weight lifting, push-ups, or leg
lifts can improve muscle fitness. As muscle fitness increases, most people
notice that they can carry heavy grocery bags more easily, pick up children
without feeling as much strain, or carry heavy items longer before getting too
tired to continue. Having stronger muscles also protects the joints.
Muscles become stronger through a three-step process:
When a person exercises against resistance, the muscles are
stressed slightly but not to the point of serious damage or injury. When the
person rests, the body rebuilds the muscles and the connective tissues between
them (joints, tendons, and ligaments) in a way that prepares them for the next
time they will be stressed. When the same muscles are stressed again, the
process is repeated, and the muscles gradually become stronger.
Many experts suggest that adults do 8 to 10 muscle-fitness exercises at
least 2 days each week. It’s best to allow at least 1 day of rest between these
exercises. A person can achieve the best results by using a resistance (such as
a dumbbell) that tires out the muscles after 8 to 12 repetitions of each
To increase muscle fitness, a person can do:
Anyone who starts an exercise program should talk to a
doctor first to see if it’s safe.
Muscular dystrophy is a rare inherited disease of the nerves and
muscles that occurs mostly in males. The most common type of muscular dystrophy
causes rapid muscle wasting and progressive weakness early in life, usually
between the ages of 2 and 5.
Muscle wasting begins in the shoulder and pelvic areas. Fat and
connective tissue may grow into muscles and cause abnormal enlargement
(hypertrophy), especially in the calf muscles of the legs. Within several years
muscular dystrophy affects the muscles of the upper body and arms. Eventually
all the major muscles are affected.
There is no cure for muscular dystrophy. Treatment involves
June 27, 2011
Adam Husney, MD - Family Medicine & Peter J. Kahrilas, MD - Gastroenterology
Myocarditis is inflammation of the heart muscle. Myocarditis may
occur after a viral, fungal, or bacterial infection, such as diphtheria,
rheumatic fever, or tuberculosis.
Treatment for myocarditis includes evaluation and treatment of the
cause of the inflammation. Treatment may require use of antibiotics,
if a bacterial infection is the cause, and medicines to relieve pain and
inflammation. Lifestyle changes, including increased rest and a low-salt diet,
may be part of the treatment.
April 26, 2012
Myoglobin is a protein found in heart tissue and other muscles. It
helps trap oxygen in the muscle cells so that the muscles can work
Myoglobin levels in the blood rise after a serious injury, such as
a heart attack or a burn. An increased level helps to diagnose a heart
Strenuous exercise, an injury to a muscle, or a shot into the
muscle can cause myoglobin levels to go up. High levels can also be caused by
heavy alcohol use. Myoglobin levels also are high in people who have kidney
failure, because myoglobin is removed from the blood by the kidneys.
August 5, 2011