DEFINITION Hurthle (HEERT-luh) cell cancer is a rare cancer that affects the thyroid gland. The thyroid is a butterfly-shaped gland in the base of your neck. It secretes hormones that are essential for regulating your body’s metabolism. Hurthle cell cancer…
DEFINITION When you have hypochondria, you become obsessed with the idea that you have a serious or life-threatening disease that hasn’t been diagnosed yet. This causes significant anxiety that goes on for months or longer, even though there’s no clear…
DEFINITION Hypertrophic cardiomyopathy (HCM) is a disease in which the heart muscle (myocardium) becomes abnormally thick (hypertrophied). The thickened heart muscle can make it harder for the heart to pump blood. Hypertrophic cardiomyopathy often goes undiagnosed because many people with…
DEFINITION Hyperparathyroidism is an excess of parathyroid hormone in the bloodstream due to overactivity of one or more of the body’s four parathyroid glands. These glands are about the size of a grain of rice and are located in your…
DEFINITION Hypothermia is a medical emergency that occurs when your body loses heat faster than it can produce heat, causing a dangerously low body temperature. Normal body temperature is around 98.6 F (37 C). Hypothermia (hi-poe-THUR-me-uh) occurs as your body…
DEFINITION Hypopituitarism is a rare disorder in which your pituitary gland either fails to produce one or more of its hormones or doesn’t produce enough of them. The pituitary is a small bean-shaped gland situated at the base of your…
DEFINITION Hiccups are involuntary contractions of the diaphragm — the muscle that separates your chest from your abdomen and plays an important role in breathing. Each contraction is followed by a sudden closure of your vocal cords, which produces the…
DEFINITION A hip fracture is a serious injury, with complications that can be life-threatening. The risk of hip fracture rises with age. Older people are at a higher risk of hip fracture because bones tend to weaken with age (osteoporosis).…
DEFINITION High blood pressure is a common condition in which the force of the blood against your artery walls is high enough that it may eventually cause health problems, such as heart disease. Blood pressure is determined by the amount…
DEFINITION Hip dysplasia is the medical term for a hip socket that doesn’t fully cover the ball portion of the upper thighbone. This allows the hip joint to become partially or completely dislocated. Most people with hip dysplasia are born…
DEFINITION A hiatal hernia occurs when part of your stomach pushes upward through your diaphragm. Your diaphragm normally has a small opening (hiatus) through which your food tube (esophagus) passes on its way to connect to your stomach. The stomach…
DEFINITION Hidradenitis suppurativa (hi-drad-uh-NIE-tis sup-yoo-ruh-TIE-vuh) is a chronic skin condition that features pea-sized to marble-sized lumps under the skin. Also known as acne inversa, these deep-seated lumps typically develop where skin rubs together — such as the armpits, groin, between…