Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «H»:
Hypotension, postural: A drop in blood
pressure (hypotension) due to a change in body position (posture) when a person moves to a more vertical position: from sitting to standing or from lying down to sitting or standing. Postural hypotension is more common in older people.
The change in position...
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Hypothalamic hamartoma: A benign tumor of the hypothalamus, the area of the brain that controls body
temperature, hunger, and thirst. (In technical terms, the hypothalamus lies beneath a structure known as the thalamus and forms the floor of the third ventricle of the brain.)
A small hypothalamic h...
Hypothalamus: The area of the brain that controls body
temperature, hunger, and thirst....
Hypothermia: Abnormally low body temperature. The condition needs treatment at body temperatures of 35C (95 F) or below. And hypothermia becomes life threatening below body temperatures of 32.2 C (90 F).
The signs and symptoms of hypothermia depend upon the body
temperature. The major initial sig...
Hypothyroid: Deficiency of thyroid hormone which is
normally made by the thyroid gland which is located in the front of
Underactivity of the thyroid gland at birth, resulting in growth retardation, developmental delay and other abnormal
features. Can be due to deficiency of iodine in the
mother's diet during pregnancy. The condition is detected
today by newborn thyroid screening. Kn...
Hypothyroidism (subnormal activity of the thyroid gland)
that starts after birth and is manifest by features
including delays in growth and development and myxedema
surfacing during infancy. Myxedema is a dry waxy type of
swelling, often with swollen lips and nose...
Hypotonia: Decreased tone of skeletal muscles. In a
floppiness. Hypotonia is a common finding in cerebral palsy and other
neuromuscular disorders. Untreated hypotonia can lead to hip
dislocation and other problems. Treatment is via physical therapy. In
some cases braces may be needed to pe...
Hypotonic solution: A solution with a lower salt concentration than in normal cells of the body and the blood. As opposed to an isotonic solution or a hypertonic solution....
Hypoventilation: The state in which a reduced amount of air enters the alveoli in the lungs, resulting in decreased levels of oxygen and increased levels of carbon dioxide in the blood. Hypoventilation can be due to breathing that is too shallow (hypopnea) or too slow (bradypnea) or to diminished lu...
Hypovolemia: An abnormal decrease in blood volume or, strictly speaking, an abnormal decrease in the volume of blood plasma. From hypo- + volume + emia (blood)....
Hypovolemic: Referring to
hypovolemia, an abnormal decrease in blood volume. As, for example, hypovolemic shock....
Hypovolemic shock: See shock. ...
Hypoxemia: abnormally low levels of oxygen in the blood. Hypoxemia may be
mild to severe and leads to shortness of breath. Low blood oxygen can result
from a variety of conditions that affect either the ability of the heart to pump
blood to the lungs to receive oxygen or the function of the lungs...