Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «H»:
Hypertrophy, benign prostatic
Hypertrophy, benign prostatic: See: Benign prostatic hyperplasia....
elevated blood level of uric acid. Uric acid is a breakdown product of purines
that are part of many foods we eat. While hyperuricemia may indicate an
increased risk of gout
, the relationship between
hyperuricemia and gout is unclear. Many...
Hyperventilation: Overbreathing. This can cause dizziness, lightheadedness, weakness, shortness of breath, a sense of
unsteadiness, muscle spasms in the hands and feet, and tingling
around the mouth and fingertips. All of these symptoms are the result of abnormally low levels of carbon dioxide in t...
Hypervolemia: An abnormal increase in blood volume or, strictly speaking, an abnormal increase in the volume of blood plasma. From hyper- + volume
+ emia (blood)....
Hypervolemic: Pertaining to hypervolemia, an abnormal increase in blood volume. For example, hypervolemic hyponatremia refers to the lowering of the blood sodium level due to hypervolemia, expansion of the blood volume....
Hypnagogic: Concerning the drowsiness
one commonly feels before sleep, the transitional state preceding sleep, and also the hallucinations that may occur at that time.
The original French word "hypnagogique" was derived from Greek roots "hypno-", sleep + "agogos", leading = leading to sleep. In the...
Hypnagogic hallucination: A vivid dreamlike hallucination that occurs as one is falling asleep. The opposite of an
hypnopompic hallucination which is a vivid dreamlike hallucination that occurs as one is waking up....
Hypnic: 1. Inducing sleep.
2. Pertaining to sleep. A hypnic jerk is a sleep start or jerk.
From the Greek hypnikos, from the Greek hypnos, sleep....
Hypnic headache: A relatively rare form of headache disorder in which the patient is awakened from sleep nightly, usually between 1 and 3am, with intense dull or throbbing pain over the whole head. Each episode may last up to 1 hour and be associated with nausea. Similar episodes may occasionally st...
Hypnic jerk: The common normal phenomenon of jerking awake, usually accompanied by a feeling of falling, just as one is drifting off to sleep. Also called a sleep jerk or sleep start....
Hypnolepsy: A neurological disorder marked by a sudden recurrent uncontrollable compulsion to sleep. Also known as narcolepsy.
The disorder is often associated with cataplexy (a sudden loss of muscle tone and paralysis of voluntary muscles associated with a strong emotion), sleep paralysis (immobi...
Hypnopompic hallucination: A vivid dreamlike hallucination that occurs as one is waking up. The opposite of an hypnagogic hallucination, which occurs as one is falling asleep....
Hypnos: The Greek and Roman god of sleep. From his name is derived the term hypnosis. Hypnos was the twin of Thanatos, the personification of death. Both Hypnos and Thanatos lived in the underworld....
Hypnosis: A part of healing from ancient times.
The induction of trance states and the use of therapeutic
suggestion were a central feature of the early Greek
healing temples, and variations of these techniques were
practiced throughout the ancient world.
Modern hypnosis began in the eighteenth...
Hypo-: Prefix meaning "low, under,
beneath, down, below normal" as in hypocalcemia (low calcium in the blood), hypoglycemia (low blood sugar) and hyposensitivity. The opposite of hypo- is hyper-.
See also: Sub-....