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.
The temporomandibular (TM) joints join the skull and lower jawbone
(mandible). These gliding "ball and socket" joints are separated by a disc made
of cartilage, which keeps the two bones from rubbing together.
These joints are located just in front of each ear. They move when
a person opens and closes the mouth.
The TM joints are stabilized by muscles that attach directly to the
jawbone. If these muscles are strained or tense, jaw pain may result.
Sometimes TM joint problems result when the cartilage disc tears or
moves out of its normal position (disc displacement).
January 11, 2012
Adam Husney, MD - Family Medicine & Arden Christen, DDS, MSD, MA, FACD - Dentistry
Temporomandibular disorder is a jaw problem that causes pain when you talk, chew, swallow, or yawn. The most common cause is tension in your jaw muscles, such as from clenching your jaw or grinding your teeth.
October 9, 2012
Tendons are tough, flexible, ropy fibers that connect muscle to
bone. Tendons vary in size and shape. And they glide smoothly over muscles as the
October 16, 2012
William H. Blahd, Jr., MD, FACEP - Emergency Medicine & Kenneth J. Koval, MD - Orthopedic Surgery, Orthopedic Trauma
Testosterone is one of the hormones needed for sexual development
and is present in both males and females. Testosterone is considered an
androgen, which is a male sex hormone, because it is made in much higher
amounts in men than in women.
Testosterone helps strengthen bones and muscles in both men and
women. In young men, testosterone signals the body to lower the voice, grow
facial hair, and develop sexual characteristics. This hormone is also needed
for sperm production.
May 17, 2012
E. Gregory Thompson, MD - Internal Medicine & Alan C. Dalkin, MD - Endocrinology
The Therapeutic Lifestyle Changes (TLC) diet is a way to eat that
lowers cholesterol. It is low in saturated fat and cholesterol, which can
reduce blood cholesterol levels and lower the risk of heart problems.
The TLC diet calls for:
The TLC diet is part of the Therapeutic Lifestyle Changes program,
which aims to lower cholesterol through diet, exercise, weight loss if needed,
and other changes, such as quitting smoking. It is recommended by the National
Cholesterol Education Program of the U.S. National Institutes of Health.
June 18, 2012
E. Gregory Thompson, MD - Internal Medicine & Rhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator
Thrombin is a substance (enzyme) in the bloodstream that is needed
for blood to clot. When a person is cut or wounded, thrombin and a protein
called fibrinogen make a stringy material that traps blood cells and then
gradually decomposes as the area heals.
Only thrombin located at the area of the injury is activated, and
only for a few seconds. This process helps prevent a potentially dangerous
blood clot, called a thrombus, from forming and traveling through the
December 28, 2011
E. Gregory Thompson, MD - Internal Medicine & Jeffrey S. Ginsberg, MD - Hematology
Thrombophlebitis is inflammation in a vein in an area where a blood
clot has formed. Often the term thrombophlebitis is shortened to
There are two types of phlebitis.
February 1, 2012
E. Gregory Thompson, MD - Internal Medicine & David A. Szalay, MD - Vascular Surgery
The thyroid is a butterfly-shaped gland that lies in front of the
windpipe, also known as the trachea, and just below the voice box, also called
the larynx. This gland makes hormones that regulate the way the body uses
The thyroid gland uses iodine from food to make two thyroid
hormones: thyroxine (T4) and triiodothyronine (T3). The thyroid gland stores
these hormones and releases them into the bloodstream as they are
If the thyroid gland does not produce enough hormones, it is
called hypothyroidism. If the gland produces too many hormones, it is called
hyperthyroidism. Problems with the thyroid gland can affect many body systems.
Changes in weight, heartbeat, body temperature, digestion, and muscle function
are common. Both hypothyroidism and hyperthyroidism can be treated, usually
with medicine and sometimes with surgery.
August 7, 2012
Kathleen Romito, MD - Family Medicine & Matthew I. Kim, MD - Endocrinology
Total cholesterol is the sum of all cholesterol measured in a
person's blood. This total includes high-density lipoprotein (HDL),
which is sometimes called the "good cholesterol," and low-density lipoprotein
(LDL), sometimes called the "bad cholesterol," and very low-density lipoprotein (VLDL).
Cholesterol is measured either in milligrams per deciliter of blood
(mg/dL) or in millimoles per liter of blood (mmol/L).
The ratio of total cholesterol to "good" (HDL) cholesterol is also
important, especially if total cholesterol is high.
July 13, 2011
Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & Carl Orringer, MD - Cardiology, Clinical Lipidology
Trans fats are primarily created through hydrogenation, a process that turns liquid oils into solids like hard margarine and shortening. Some foods with trans fats include vegetable shortening, some margarines, crackers, cookies, and many packaged snack foods. Some animal-based foods have small amounts of naturally occurring trans fats.
Trans fats do not spoil as quickly as liquid fats, which makes them better in foods that are packaged for a long time.
Trans fat can increase cholesterol levels the same way as saturated fat. The best way to check for trans fat in a food is to look at the list of ingredients. Food made with partially hydrogenated or hydrogenated oil will have trans fat.
January 25, 2013
Kathleen Romito, MD - Family Medicine & Rhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator
A transcutaneous blood oxygen monitor is used to help doctors
find out whether a person needs supplemental oxygen or an adjustment to the
amount of supplemental oxygen they are already receiving. A sensor attached to
the person's finger connects to a machine that gives a reading of the oxygen
level in the person's blood.
This test does not require taking a sample of a person's
October 11, 2011
John Pope, MD - Pediatrics & Larry A. Latson, MD - Pediatric Cardiology
Transcutaneous electrical nerve stimulation (TENS) is a therapy
that uses mild electrical current to treat pain.
Current is delivered through small pieces of material that conduct
electricity (electrodes). These are placed on the skin near the source of pain.
When the current is delivered, some people experience less pain. This may be
because electricity from the electrodes stimulates the nerves in an affected
area and sends signals to the brain that "scramble" normal pain signals.
Another theory is that the electrical stimulation of the nerve may help the
body to produce natural painkillers called endorphins, which may block the
perception of pain.
January 9, 2013
Anne C. Poinier, MD - Internal Medicine & Nancy Greenwald, MD - Physical Medicine and Rehabilitation
In a transesophageal echocardiogram, a transducer is inserted
through the mouth and down the throat into the esophagus. High-pitched sound
waves (ultrasound) are sent through the transducer to produce an image of the
heart and sometimes the aorta.
Normally the transducer is moved over the surface of the skin on
A transesophageal echocardiogram is often used for obese people
because evaluating the heart through a thick chest wall is hard. This
method allows a clear view of the valves and their ability to function. It
provides a better view of heart valves than a standard transthoracic
echocardiogram, but the procedure is more complicated.
December 9, 2011
Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & George Philippides, MD - Cardiology
A transient ischemic attack (TIA) happens when blood flow to part of the brain is stopped for a short time. It's also called a mini-stroke because the symptoms are like those of a stroke but they don't last long or cause lasting damage.
A TIA is a warning that you may have a stroke in the future. Early treatment can help prevent a stroke.
E. Gregory Thompson, MD - Internal Medicine & Richard D. Zorowitz, MD - Physical Medicine and Rehabilitation
In transposition of the great vessels, the major blood vessels
attached to the heart—the aorta and the pulmonary artery—are reversed. This
reversal results in the blood going to the wrong places. This leads to low oxygen levels in the body.
The aorta, which normally carries oxygen-rich blood from the left
side of the heart to the body, instead receives oxygen-poor blood from the
right side of the heart. The pulmonary artery, which normally carries
oxygen-poor blood from the right side of the heart to the lungs, instead
receives oxygen-rich blood from the left side of the heart.
In transposition of the great vessels, the right lower chamber of
the heart (rather than the left lower chamber) pumps blood to the body.
But the right side of the heart normally is not strong enough to pump
blood effectively to the whole body. This increased workload on the right side
of the heart can lead to a weakened heart.
There are several types of transposition of the great vessels. Each
has slightly different placement of the vessels and openings that result in
mixing of blood between the two sides of the heart. The most common form of
transposition of the great vessels results in oxygen-poor blood being pumped to
Certain other heart defects must be present
to allow a child with transposition of the great vessels to live. Other defects
ultimately compensate for the transposition of the great vessels by allowing
oxygen-rich blood to mix with oxygen-poor blood so that some oxygen can get to the tissues of the body. Surgery is usually
needed for long-term survival.
Trigeminal neuralgia (sometimes called tic douloureux) is a sudden,
sharp pain on one side of the face. The pain commonly starts near one side of
the mouth, then shoots toward the ear, eye, or nostril on the same side of the
The pain may start with a touch, movement, air drafts, eating, or
for no known reason. Symptom-free periods, called remissions, may last several
months or longer. As the condition gets worse, though, the episodes of pain
become more frequent, remissions become shorter and less common, and a dull
ache may remain between the episodes of stabbing pain.
Trigeminal neuralgia is most common in middle and late life. It
affects women more often than men. When trigeminal neuralgia occurs in young
people, it is often caused by multiple sclerosis.
Treatment with medicine is usually helpful. Surgery may be
helpful if a structural problem (such as a blood vessel pressing on the
trigeminal nerve) is the cause.
July 20, 2012
William H. Blahd, Jr., MD, FACEP - Emergency Medicine & H. Michael O'Connor, MD - Emergency Medicine
Triglycerides are a type of fat found in your blood. You need some triglycerides for good health. But high levels of triglycerides raise your risk for heart disease and other serious problems.
Your triglycerides are measured by the same blood test that measures your cholesterol.
Kathleen Romito, MD - Family Medicine & Robert A. Kloner, MD, PhD - Cardiology & Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology
A normal pregnancy lasts about 40 weeks from conception to the
birth of a baby. This time is roughly divided into 3 periods: the first
trimester, from conception to about the 12th week of pregnancy; the second
trimester, from about 13 to 27 weeks of pregnancy; and the third trimester,
from about 28 weeks of pregnancy until birth.
Each trimester of pregnancy is marked by developmental changes in
July 23, 2012
Sarah Marshall, MD - Family Medicine & Kirtly Jones, MD - Obstetrics and Gynecology
The trunk, or torso, is the part of the body to which the head,
arms, and legs connect. It includes the shoulders, chest, lower abdomen, back,
March 4, 2011
Adam Husney, MD - Family Medicine & David A. Fleckenstein, MPT - Physical Therapy
Tuberculosis (TB) is an infection caused by bacteria. It usually affects the lungs. Symptoms may include fever, extreme fatigue, weight
loss, night sweats, and a cough that brings up thick, bloody mucus.
TB can be deadly if it isn't treated.
E. Gregory Thompson, MD - Internal Medicine & R. Steven Tharratt, MD, MPVM, FACP, FCCP - Pulmonology, Critical Care Medicine, Medical Toxicology
Type 1 diabetes is a lifelong disease that happens when the pancreas stops making insulin. It usually develops in children and young adults.
Insulin lets sugar (glucose) move from the blood into the body's cells, where it can be used for energy or stored. Without insulin, sugar can't get into the cells, and your blood sugar gets too high. Over time, high blood sugar can lead to problems with your eyes, heart, blood vessels, nerves, and kidneys.
Treatment for type 1 diabetes focuses on keeping your blood sugar level in a safe range by eating a balanced diet, taking insulin injections, and getting regular exercise.
E. Gregory Thompson, MD - Internal Medicine & Jennifer Hone, MD - Endocrinology, Diabetes and Metabolism
Type 2 diabetes is a lifelong disease that happens when your body can't use insulin the right way or when your pancreas can't make enough insulin. It often affects people who are overweight and not physically active.
Insulin helps sugar (glucose) move from the blood into the body's cells, where it can be used for energy or stored. Without insulin, sugar can't get into the cells, and your blood sugar gets too high. Over time, high blood sugar can lead to problems with your eyes, heart, blood vessels, nerves, and kidneys.
You may be able to manage diabetes by eating a balanced diet and getting regular exercise. But some people need medicines to help control their blood sugar levels.