Glossary of Diabetes - H

H

HCF diet

A high-carbohydrate, high-fiber diet.

Hemochromatosis

A condition in which excess iron levels are deposited in body tissues, damaging them. Characteristically, it causes diabetes among its other effects. It can be caused too much iron intake (the normal body conserves iron very well, and has few routes for discarded excess iron). In an inherited form, it is the most common genetic diseases in those of Northern European ancestry. It is less common in other populations. See: Bronze diabetes.

Hemodialysis

A mechanical method of cleaning the blood for people who have kidney disease. See also: Dialysis.

Hemoglobin A1C (HbA1c)

Hemoglobin is the substance in red blood cells that carries oxygen to the cells. Hemoglobin reacts with blood glucose in various ways; the HbA1c sub-type reacts irreversibly. Since blood cells live about 90 days or so, the amount of HbA1c present at any time is a record of how much glucose has been in the blood during that period. It is therefore a record of the average blood glucose level over that period, though it is biased toward more recent conditions during that period.

Heredity

inheritance of various traits. One's heredity is the "sum" of one's genes, and their expression, passed on by one's parents. An additional, and poorly understood, source of inherited traits is exogenetic inheritance in which alterations to genetic material during life (e.g., from chemical exposures) changes the expression of genes which are passed to offspring.

High

The state of having high blood sugar.

High blood pressure

The pressure of blood in the arteries has normal values in a population. Blood pressure in an individual which is characteristically higher than that value is called high blood pressure. Exercise, psychological state (including the mere presence of medical folk in some cases), disease, and so on all affect blood pressure, so the determination is a statistical one. Higher than normal blood pressure is associated with, and perhaps even casual for some, assorted pathologies. Diabetics have higher rates of cardiovascular disease and higher rates of high blood pressure.

Hives

a skin condition caused, in most cases, by an allergic reaction to some substance or substances.

HLA antigens

Proteins on the outer part of body cells that are (effectively) unique to that person. HLA types are inherited, and some of them are connected with Type I diabetes in that their presence is a marker (or a cause?) of the susceptibility to an external trigger for the auto-immune reaction which attacks beta cells.

Home blood glucose monitoring

A way a person can test how much glucose (sugar) is in the blood. Also called self-monitoring of blood glucose. See also: Blood glucose monitoring.

Homeostasis

the operation of body systems which has the effect of keeping assorted conditions in an effectively constant state. Thus, if you drink lots of water, your body reacts by producing more urine. Increased salt intake results in increased salt excretion. Lowered environmental temperature eventually starts chills and shivers, thus producing more heat by muscular activity. First explicitly noted in the 19th century by Claude Bernard who named it.

Hormone

a chemical released by one of the endocrine glands or tissues, and which has effects on other tissues. Insulin is a hormone as are glucagon, adrenaline, and angiotensin II.

Human insulin

Man-made insulins that is identical to the insulin produced by your own body. It is produced by bacteria which have had insulin genes installed into them. Human insulin has been available since October 1982. Genentech developed the first production mechanism.

Hyperglycemia

a condition in which glucose levels are higher than usual.

Hyperinsulinism

Too high a level of insulin in the blood. This often involves a condition in which the body produces too much insulin. Researchers believe that this condition may play a role in the development of noninsulin-dependent diabetes (or perhaps its side-effects) and in hypertension. See also: Syndrome X.

Hyperlipemia

See: Hyperlipidemia.

Hyperlipidemia

Too high a level of fats (lipids) in the blood. See also: Syndrome X.

Hyperosmolar coma

A coma (loss of consciousness) related to high levels of glucose (sugar) in the blood and requiring emergency treatment. A person with this condition is usually older and weak from loss of body fluids and weight. The person may or may not have a previous history of diabetes. Ketones (acids) are not typically present in the urine.

Hypertension

a condition in which blood pressure is higher than normal. See high blood pressure.

Hypoglycemia

a condition in which blood glucose levels are lower than normal. This can be caused by an overdose of insulin (too much or wrong type) relative to the amount and type of food and/or exercise.

Hypotension

Low blood pressure or a sudden drop in blood pressure. A person rising quickly from a sitting or reclining position may have a sudden fall in blood pressure, causing dizziness or fainting. See autonomic neuropathy.