Health, diseases terms glossary - Starting with H

Hair follicle: Hair follicle- a tiny opening in the skin from which a hair grows
Halitosis: Halitosis- the clinical term for bad breath; commonly caused by poor oral hygiene or eating certain foods; if persistent it can be a sign of illness
Hallucination: Hallucination- a perception that occurs when there is actually nothing to cause it (such as hearing voices when there are none)
Hammer toe: Hammer toe- an abnormality in the tendons of the toe that causes the toe to be flexed at all times
Hashimoto’s disease: Hashimoto’s disease- a disease in which the body’s immune system attacks cells of the thyroid gland, resulting in a decrease in thyroid hormones
Hay fever: Hay fever- the common name for allergic rhinitis
Heart: Heart-lung machine- a machine that takes over the functions of the heart and lungs during certain types of surgery
Heart block: Heart block- a disorder of the heart caused by a blockage of the nerve impulses to the heart that regulate heartbeat; may lead to dizziness, fainting, or stroke
Heart failure: Heart failure- the inability of the heart to pump blood effectively
Heartburn: Heartburn- a burning sensation experienced in the center of the chest up to the throat; may be caused by overeating, eating spicy food, or drinking alcohol; recurrent heartburn may be caused by acid reflux
Heat stroke: Heat stroke- a life-threatening condition resulting from extreme overexposure to heat, which disrupts the body's system of regulating temperature
Heel spur: Heel spur- an abnormal, often painful outgrowth of bone on the back of the heel
Hematocrit: Hematocrit- the percentage of total blood volume that consists of red blood cells, which is determined by laboratory testing; can be an indicator of disease or injury
Hematuria: Hematuria- blood in the urine, which can be caused by urinary tract disorders (such as cysts, tumor, or stones) or by an infection
Hemochromatosis: Hemochromatosis- a genetic disorder in which too much iron is absorbed from food
Hemodialysis: Hemodialysis- A mechanical method of cleaning the blood for people who have kidney disease. See also: Dialysis.
Hemodialysis: Hemodialysis- a method used to treat kidney failure, in which blood is passed through a machine that purifies it and returns it to the body
Hemoglobin: Hemoglobin- the pigment in red blood cells that is responsible for carrying oxygen; hemoglobin bound to oxygen gives blood its red color
Hemoglobin A1C (HbA1c): Hemoglobin A1C (HbA1c)- The substance of red blood cells that carries oxygen to the cells and sometimes joins with glucose (sugar). Because the glucose stays attached for the life of the cell (about 4 months), a test to measure hemoglobin A1C shows what the person’s average blood glucose level was for that period of time.
Hemoglobin A1c (HbA1c) test: Blood test to find the blood sugar level a person has averaged over a 2- to 3-month period

Glossary