DEFINITION Type 2 diabetes, once known as adult-onset or noninsulin-dependent diabetes, is a chronic condition that affects the way your body metabolizes sugar (glucose), your body’s important source of fuel. With type 2 diabetes, your body either resists the effects…
DEFINITION Tularemia is a rare infectious disease that typically attacks the skin, eyes, lymph nodes and lungs. Tularemia — also called rabbit fever or deer fly fever — is caused by the bacterium Francisella tularensis. The disease mainly affects mammals,…
DEFINITION Turner syndrome, a condition that affects only girls and women, results when a sex chromosome (the X chromosome) is missing or partially missing. Turner syndrome can cause a variety of medical and developmental problems, including short height, failure to…
DEFINITION Truncus arteriosus (TRUNG-kus ahr-teer-e-O-sus) is a rare heart defect that’s present at birth (congenital). If your baby has truncus arteriosus, it means that one large blood vessel leads out of the heart. Normally, there are two separate vessels coming…
DEFINITION Tuberculosis (TB) is a potentially serious infectious disease that mainly affects your lungs. The bacteria that cause tuberculosis are spread from one person to another through tiny droplets released into the air via coughs and sneezes. Once rare in…
DEFINITION Tuberous sclerosis (TWO-bur-uhs skluh-ROH-sis), also called tuberous sclerosis complex, is a rare genetic disease that causes noncancerous (benign) tumors to grow in many parts of the body. The signs and symptoms of tuberous sclerosis vary widely, depending on where…
DEFINITION Traumatic brain injury occurs when an external mechanical force causes brain dysfunction. Traumatic brain injury usually results from a violent blow or jolt to the head or body. An object penetrating the skull, such as a bullet or shattered…
DEFINITION Transverse myelitis is an inflammation of the spinal cord, which often targets insulating material covering nerve cell fibers (myelin). Transverse myelitis may result in injury across the spinal cord, affecting sensation below the injury. The disrupted transmission of nerve…
DEFINITION Trachoma (truh-KOH-muh) is a bacterial infection that affects your eyes. The bacterium that causes trachoma spreads through direct contact with the eyes, eyelids, and nose or throat secretions of infected people. Trachoma is very contagious and almost always affects…
DEFINITION Toxic hepatitis is an inflammation of your liver in reaction to certain substances to which you’re exposed. Toxic hepatitis can be caused by alcohol, chemicals, drugs or nutritional supplements. In some cases, toxic hepatitis develops within hours or days…
DEFINITION A tooth abscess is a pocket of pus that’s caused by a bacterial infection. The abscess can occur at different regions of the tooth for different reasons. A periapical (per-e-AP-ih-kul) abscess occurs at the tip of the root, whereas…
DEFINITION Tonsillitis is inflammation of the tonsils, two oval-shaped pads of tissue at the back of the throat — one tonsil on each side. Signs and symptoms of tonsillitis include swollen tonsils, sore throat, difficulty swallowing and tender lymph nodes…