Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «H»:
Heat cramps: Painful muscle spasms in the abdomen, arms, or legs following strenuous activity. The skin is usually moist and cool and the pulse is normal or slightly raised. Body temperature is mostly normal. Heat cramps often are caused by a lack of salt in the body, but salt replacement should no...
Heat exhaustion: A warning that the body is getting too hot. The person may be thirsty, giddy, weak, uncoordinated, nauseous, and sweating profusely. The body temperature is usually normal and the pulse is normal or raised. The skin is cold and clammy. Although heat exhaustion often is caused by th...
Heat index: The temperature the body feels when heat and humidity are combined. The body dissipates heat by varying the rate and depth of blood circulation, by losing water through the skin and sweat glands, and as a last resort, by panting, when blood is heated above 98.6°F (37° C). Sweatin...
Heat prostration: Overheating of the body due to
extreme weather conditions. Unrelieved hyperthermia can
lead to collapse and death, particularly in the elderly.
Prevention via air conditioning, ventilation, and drinking
extra water is the key for vulnerable persons. In emergency
Heat rash (Pictures)
Heat rash: Heat rash is an irritation of
the skin that results from excessive
sweating during hot and
humid weather. Heat rash appears as clusters of red pimples or blisters on the skin. It is more likely to occur on the neck and upper chest, in the groin, under the breasts, and in elbow creases....
Heat stroke: A core body temperature that rises above 104 F (40 C) accompanied by hot, dry skin and central nervous system abnormalities such as delirium, convulsions, or coma. Heat stroke that results from exposure to a high environmental temperature is called nonexertional heat stroke. Heat strok...
Heat syncope: Sudden dizziness, feeling faint ans sometimes fainting experienced after exercising in the heat. The skin appears pale and sweaty but is generally moist and cool. The pulse may be weakened, and the heart rate is usually rapid. Body temperature is normal....
Heat-related illness: A person with symptoms including headache, nausea, and fatigue after exposure to heat probably has some measure of a heat-related illness. It is important to recognize the difference between the very serious condition known as heat stroke and other heat-related illnesses. Pers...
Heatliness: A characteristic of certain foods or other substances believed to cause emotional or physical reactions associated with temper, fever, passion, and excess.
Coolness and heatliness are the yin and yang of a principle of Chinese philosophy. Heatiness produces a feeling of unpleasant warmt...
Heberden disease: There are two different Heberden diseases:
Angina pectoris, chest pain
that is often severe and crushing, due to an inadequate
supply of oxygen to the heart muscle.
Osteoarthritis of the small joints with nodules
(Heberden nodes) in and about the last joint of the
Heberden node: A small fixed
bump on the finger, usually at the last joint of the
finger, Heberden's node is a calcified spur of the joint
(articular) cartilage and is a sign of osteoarthritis.
Named for the English physician William
Heberden (1710-1801) who made a number of celebrated
Hecht syndrome: A striking genetic disorder in which abnormally short muscles in the jaw make it impossible to open the mouth fully (trismus) and abnormally short muscles in the hands keep the fingers straight when the hand is flexed back (pseudocamptodactyly). The difficulty in opening the mouth fu...
Hecht's pneumonia: Also known as giant cell pneumonia, this is a deadly but fortunately rare complication of measles. It tends to strike children who are immunodeficient as from leukemia or HIV/AIDS. The postmortem examination (autopsy) shows multinucleated giant cells lining the alveoli (air sacs...
Hecht-Beals syndrome: See: Hecht syndrome....
Hedonophobia: An abnormal, excessive, and persistent fear of pleasure. Sufferers with this most puritanical of phobias typically feel guilty about experiencing pleasure even though they usually realize rationally there is nothing at all wrong with taking pleasure. Their guilt usually arises from the...