DEFINITION Cavities are permanently damaged areas in the hard surface of your teeth that develop into tiny openings or holes. Cavities, also called tooth decay or caries, are caused by a combination of factors, including bacteria in your mouth, frequent…
DEFINITION Carcinoid tumors are a type of slow-growing cancer that can arise in several places throughout your body. Carcinoid tumors, which are one subset of tumors called neuroendocrine tumors, usually begin in the digestive tract (stomach, appendix, small intestine, colon,…
DEFINITION Carbon monoxide poisoning occurs when carbon monoxide builds up in your bloodstream. When too much carbon monoxide is in the air, your body replaces the oxygen in your red blood cells with carbon monoxide. This can lead to serious…
DEFINITION Carcinoid syndrome occurs when a rare cancerous tumor called a carcinoid tumor secretes certain chemicals into your bloodstream, causing a variety of signs and symptoms. Carcinoid tumors occur most commonly in the gastrointestinal tract or lungs. …
DEFINITION Calciphylaxis (kal-sih-fuh-LACK-sis) is a serious, uncommon disease in which calcium accumulates in small blood vessels of the fat and skin tissues. People who have this condition usually have kidney failure and are on dialysis or recently had a kidney…
DEFINITION Central nervous system vascular malformations are rare abnormalities of blood vessels in your brain or spinal cord and their membranes. Types types of central nervous system vascular malformations include: Arteriovenous malformations. A brain (intracranial)…
DEFINITION Cardiogenic shock is a condition in which your heart suddenly can’t pump enough blood to meet your body’s needs. The condition is most often caused by a severe heart attack. Cardiogenic shock is rare, but it’s…
DEFINITION Cancer of the ureter begins in the cells that line the inside of the tubes (ureters) that connect your kidneys to your bladder. Ureters are part of the urinary tract, and they carry urine produced by the kidneys to…
DEFINITION Cardiomyopathy (kahr-dee-o-my-OP-uh-thee) is a condition where the heart muscle is abnormal. The main types of cardiomyopathy include dilated, hypertrophic and restrictive cardiomyopathy. Cardiomyopathy makes it harder for your heart to pump and deliver blood to the rest of your…
DEFINITION Carotid artery disease occurs when fatty deposits (plaques) clog the blood vessels that deliver blood to your brain and head (carotid arteries). The blockage increases your risk of stroke, a medical emergency that occurs when the blood supply to…
DEFINITION Canker sores, also called aphthous ulcers, are small, shallow lesions that develop on the soft tissues in your mouth or at the base of your gums. Unlike cold sores, canker sores don’t occur on the surface of your lips…
DEFINITION Bullous pemphigoid (BUL-us PEM-fih-goid) is a rare skin condition that causes large, fluid-filled blisters on areas of skin that often flex — such as the lower abdomen, upper thighs or armpits. Bullous pemphigoid is most common in people older…