Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «H»:
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hCG
hCG: Human chorionic gonadotropin, a human hormone made by chorionic cells in the fetal part of the placenta. Human chorionic gonadotropin (hCG) is directed at the gonads and stimulates them. Hence, the name "gonadotropin."
The presence of hCG is detectable by immunologic means within days of fert...
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HCM
HCM: Hypertrophic cardiomyopathy....
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Hct (hematocrit)
Hct (hematocrit): Abbreviation for hematocrit.
The hematocrit is the proportion, by volume, of the blood that
consists of red blood cells. The hematocrit (hct) is expressed as a
percentage.
For example, an hematocrit of 25% means that there are 25
milliliters of red blood cells in 100 millilite...
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HCV
HCV: Hepatitis C virus....
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HDL
HDL: High density lipoprotein.
Lipoproteins are combinations of lipids (fats) and proteins. They are the form in which lipids are transported in the blood. The high density lipoproteins transport cholesterol from the tissues of the body to the liver so it can be gotten rid of in the bile.
HDL ch...
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HDL cholesterol
HDL cholesterol: Lipoproteins,
which are
combinations of lipids (fats) and proteins, are the form in which
lipids are transported in the blood. The high-density lipoproteins
transport
cholesterol from the tissues of the body to the liver so it can be
gotten rid of (in the bile). HDL
cholester...
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HDR syndrome
HDR syndrome: The syndrome of familial Hypoparathyroidism, sensorineural Deafness, and Renal dysplasia. Inherited as an autosomal dominant trait, the syndrome is caused by haploinsufficiency of the GATA3 gene in chromosome 10p.
The hypoparathyroidism causes hypocalcemia (a low level of calcium in...
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HDV
HDV: Hepatitis D virus....
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Head and neck cancer
Head and neck cancer: The common carcinomas of the oral cavity, pharynx, and larynx as well as other tumors that affect the head and neck.
These include:
Paranasal sinus and nasal cavity cancer
Lip and oral cavity cancer
Nasopharyngeal cancer
Oropharyngeal cancer
Hypopharyngeal cancer
Laryngeal...
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Head bones
Head bones: There are 29 bones in the human head. They consist of 8 cranial bones, 14 facial bones, the hyoid bone, and 6 auditory (ear) bones.
The 8 cranial bones are the frontal, 2 parietal, occipital, 2 temporal, sphenoid, and ethmoid bones.
The 14 facial bones are the 2 maxilla, mandible, 2 zy...
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Head injury
Head injury: Damage to any of the structures of the head as a result
of trauma. While the term "head injury" is most often used to refer to an injury
to the brain, head injuries may also involve the bones, muscles, blood vessels,
skin, and other organs of the face or head. A head injury...
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Head lice
Head lice: Pediculus humanus capitis, parasitic
insects found on the heads of people. Head lice are most
often found on the scalp behind the ears and near the
neckline at the back of the neck. The lice hold onto the hair
with hook-like claws at the end of each of their six legs.
Head lice are r...
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Head, optic nerve
Head, optic nerve: The circular area in the back of the inside of the eye where the optic nerve connects to the retina....
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Headache
Headache: A pain in the head with the pain being above the eyes or the ears, behind the head (occipital), or in the back of the upper neck. Headache, like chest pain or back ache, has many causes.
All headaches are considered primary headaches or secondary headaches. Primary headaches are not associ...
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Headache, alarm clock
Headache, alarm clock: See: Alarm clock headache....
