Hypo: From 3 Different Sources
A prefix meaning under, below, or less than normal.
A pre?x meaning below, under, or less than normal: for example, hypotension (low blood pressure) and hypodermic (under the skin).
prefix. see hyp-.
A fall in blood pressure below the normal level... hypotension
A de?ciency of glucose in the blood – the normal range being 3·5–7·5 mmol/l (see DIABETES MELLITUS). It most commonly occurs in diabetic patients – for example, after an excessive dose of INSULIN and heavy exercise, particularly with inadequate or delayed meals. It may also occur in non-diabetic people, however: for example, in very cold situations or after periods of starvation. Hypoglycaemia is normally indicated by characteristic warning signs and symptoms, particularly if the blood glucose concentration is falling rapidly. These include anxiety, tremor, sweating, breathlessness, raised pulse rate, blurred vision and reduced concentration, leading – in severe cases – to unconsciousness. Symptoms may be relieved by taking some sugar, some sweet biscuits or a sweetened drink. In emergencies, such as when the patient is comatose (see COMA), an intramuscular injection of GLUCAGON or intravenous glucose should be given. Early treatment is vital, since prolonged hypoglycaemia, by starving the brain cells of glucose, may lead to irreversible brain damage.... hypoglycaemia
Greatly decreased temperature... hypothermia
Lack of sufficient oxygen, such as occurs at high altitudes.... hypoxia
A SERUM concentration of calcium below the normal range (between 2.33 and 3.05 mmol of calcium per 100 ml of serum). This may cause TETANY, acutely; chronically it may give rise to RICKETS, OSTEOMALACIA or osteoporosis (see BONE, DISORDERS OF). It may be caused by hypoparathyroidism (see THYROID GLAND, DISEASES OF), vitamin D de?ciency (see APPENDIX 5: VITAMINS), malabsorption, renal failure or acute pancreatitis (see PANCREAS, DISORDERS OF).... hypocalcaemia
An abnormally low concentration of potassium in the blood.... hypokalaemia
Underactivity of the parathyroid glands (see under ENDOCRINE GLANDS). Thus there is a lack of parathyroid hormone resulting in HYPOCALCAEMIA. It may be caused by inadvertent removal of the glands when the thyroid gland is surgically removed, or by failure of the glands because of autoimmune disease.... hypoparathyroidism
Underactivity of the PITUITARY GLAND. It can cause dwar?sm, delayed puberty, impotence, infertility, AMENORRHOEA, hypothyroidism (see THYROID GLAND, DISEASES OF), and hypoadrenalism. Causes include tumours, irradiation of the gland, SARCOIDOSIS, and necrosis associated with post-partum haemorrhage (Sheehan’s syndrome).... hypopituitarism
A part of the diencephalon of the brain, it is a major actor in the limbic system. This is a functional, not anatomic, system in the brain that influences and is influenced by emotions. Call the limbic system an ad hoc committee that decides how things are going today, based on past, present, potential, and myriad informational inputs from the somatic body. The hypothalamus gathers the data and sets the levels of the pituitary thermostat. The pituitary does what the hypothalamus tells it to do, and our whole chemical nervous system responds to the pituitary, which responds to the hypothalamus, which, along with the rest of the limbic system, decides the kind of day we need to get ready for. And to think that some doctors used to (and still) scoff at a “psychosomatic disorder.”... hypothalamus
An insu?cient secretion of HYDROCHLORIC ACID from the digestive cells of the stomach lining.... hypochlorhydria
The regions of the belly below the ribcage and to the sides, as in left or right hypochondrium.... hypochondrium
The 12th cranial nerve, which supplies the muscles of the tongue, together with some others lying near it. This nerve is responsible for movements required for swallowing and talking. (See also NERVOUS SYSTEM.)... hypoglossal nerve
A condition characterised by underactivity of the testes (see TESTICLE) or OVARIES – the gonads. The condition may be caused by a genetically based disorder resulting in an abnormally functioning gonad (primary hypogonadism) or by a malfunctioning PITUITARY GLAND that fails to produce an adequate amount of gonadotrophin hormone (see GONADOTROPHINS) – secondary hypogonadism. Those affected may fail to develop adequately the secondary characteristics of their sex: males will have delayed puberty, erectile impotence and infertility and also develop GYNAECOMASTIA; females also have delayed puberty, infertility, and sometimes HIRSUTISM.... hypogonadism
Hypomania is a modest manifestation of mania (see under MENTAL ILLNESS). The individual is elated to an extent that he or she may make unwise decisions, and social behaviour may become animated and uninhibited. To the casual observer individuals may, however, seem normal. Treatment is advisable to prevent them from harming their own or their family’s interests. Treatment is as for mania.... hypomania
Surgical excision of the PITUITARY GLAND. This can be done by opening the skull, by inserting very low-temperature needles (CRYOSURGERY) into the gland, or by inserting needles of radioactive YTTRIUM-90.... hypophysectomy
Excessive smallness of an organ or part, arising from imperfect development.... hypoplasia
A developmental abnormality in the male, in which the URETHRA opens on the undersurface of the penis or in the PERINEUM. The condition is treatable with surgery, but several operations over a period of years may be required to ensure normal urinary and sexual functions.... hypospadias
Tending to lower blood pressure... hypotensive
Underactivity of the thyroid gland (see THYROID GLAND, DISEASES OF).... hypothyroidism
A reduced circulating blood volume. Acutely, it is caused by unreplaced losses from bleeding, sweating, diarrhoea, vomiting or diuresis. Chronically it may be caused by inadequate ?uid intake.... hypovolaemia
A blood tension of carbon dioxide below normal. It is produced by HYPERVENTILATION which may be voluntary, mechanical (if the patient is on a ventilator) or in response to a physiological insult such as metabolic acidosis or brain injury.... hypocapnia
A term pertaining to the region immediately under the skin. Thus, a hypodermic injection means an injection given underneath the skin. A hypodermic syringe is a small syringe which, ?tted with a ?ne needle, is used to give such injections.... hypodermic
A lower-than-normal amount of the protein GAMMA-GLOBULIN in the blood. The origin may be genetic – several types are inherited – or an acquired defect (for instance, some lymphomas cause the condition). Gamma-globulin largely comprises antibodies (IMMUNOGLOBULINS) so de?ciency of the protein reduces an individual’s natural resistance to infection (see IMMUNOLOGY).... hypogammaglobulinaemia
A SERUM concentration of sodium below the normal range. It may be produced by dilution of blood (giving large volumes of salt-poor solutions intravenously), excessive water retention (inappropriate secretion of antidiuretic hormone), excessive sodium loss, and, rarely, by inadequate salt intake.... hyponatraemia
Another name for the PITUITARY GLAND.... hypophysis
The condition, or state, characterised by HYPOTENSION, or abnormally low blood pressure.... hypopiesis
A fall in the amount of PROTEIN in the blood. This may be caused by malnutrition, loss of protein from kidney disorders, or faulty production of protein which occurs in some liver disorders. Hypoproteinaemia causes OEDEMA because ?uid accumulates in the tissues as a consequence of the metabolic abnormalities. Patients’ resistance to infections is also impaired.... hypoproteinaemia
The term applied to the condition in which blood accumulates in a dependent part of the body as a result of poor circulation. Congestion of the base of the lungs in old people from this cause, and infection, is called hypostatic PNEUMONIA.... hypostasis
Shallow and/or slow breathing, often caused by the effects of injury or drugs on the respiratory centre. It causes HYPERCAPNIA and HYPOXIA.... hypoventilation
A fall in the concentration of OXYGEN in the arterial blood. Symptoms are those of CYANOSIS and, if severe, the affected individual will show signs of respiratory failure.... hypoxaemia
The statistical hypothesis that one variable has no association with another variable or set of variables, or that two or more population distributions do not differ from one another. In simplest terms, the null hypothesis states that the results observed in a study, experiment or test are no different from what might have occurred by chance alone.... null hypothesis
A disinfectant by virtue of the fact that it gives o? chlorine. For domestic use – as, for example, for sterilising baby feeding bottles – it is available in a variety of proprietary preparations.... sodium hypochlorite
A preventive treatment of allergy to specific substances, such as grass pollens and insect venom. Hyposensitization involves giving gradually increasing doses of the allergen so that the immune system becomes less sensitive to that substance. The treatment, which may need to be repeated annually for a few years, carries the risk of anaphylactic shock.... hyposensitization
See hypotension.... postural hypotension
A state of mind in which the sufferer is much preoccupied with his health... hypochonodriasis
Having low adrenocortical function.... hypocortical
Little transmission, effect on general population not important.... hypoendemic
A term means pertaining to the lower middle part of the abdomen, just above the pubis.... hypogastric
Lowering the level of blood sugar in the body... hypoglycement
These oral agents reduce the excessive amounts of GLUCOSE in the blood (HYPERGLYCAEMIA) in people with type 2 (INSULIN-resistant) diabetes (see DIABETES MELLITUS). Although the various drugs act di?erently, most depend on a supply of endogenous (secreted by the PANCREAS) insulin. Thus they are of no value in treating patients with type 1 diabetes (insulin-dependent diabetes mellitus (IDDM), in which the pancreas produces little or no insulin and the patient’s condition is stabilised using insulin injections). The traditional oral hypoglycaemic drugs have been the sulphonylureas and biguanides; new agents are now available – for example, thiazolidine-diones (insulin-enhancing agents) and alpha-glucosidase inhibitors, which delay the digestion of CARBOHYDRATE and the absorption of glucose. Hypoglycaemic agents should not be prescribed until diabetic patients have been shown not to respond adequately to at least three months’ restriction of energy and carbohydrate intake.
Sulphonylureas The main group of hypoglycaemic agents, these act on the beta cells to stimulate insulin release; consequently they are e?ective only when there is some residual pancreatic beta-cell activity (see INSULIN). They also act on peripheral tissues to increase sensitivity, although this is less important. All sulphonylureas may lead to HYPOGLYCAEMIA four hours or more after food, but this is relatively uncommon, and usually an indication of overdose.
There are several di?erent sulphonylureas; apart from some di?erences in their duration or action (and hence in their suitability for individual patients) there is little di?erence in their e?ectiveness. Only chlorpropamide has appreciably more side-effects – mainly because of its prolonged duration of action and consequent risk of hypoglycaemia. There is also the common and unpleasant chlorpropamide/ alcohol-?ush phenomenon when the patient takes alcohol. Selection of an individual sulphonylurea depends on the patient’s age and renal function, and often just on personal preference. Elderly patients are particularly prone to the risks of hypoglycaemia when long-acting drugs are used. In these patients chlorpropamide, and preferably glibenclamide, should be avoided and replaced by others such as gliclazide or tolbutamide.
These drugs may cause weight gain and are indicated only if poor control persists despite adequate attempts at dieting. They should not be used during breast feeding, and caution is necessary in the elderly and in those with renal or hepatic insu?ciency. They should also be avoided in porphyria (see PORPHYRIAS). During surgery and intercurrent illness (such as myocardial infarction, COMA, infection and trauma), insulin therapy should be temporarily substituted. Insulin is generally used during pregnancy and should be used in the presence of ketoacidosis.
Side-effects Chie?y gastrointestinal disturbances and headache; these are generally mild and infrequent. After drinking alcohol, chlorpropamide may cause facial ?ushing. It also may enhance the action of antidiuretic hormone (see VASOPRESSIN), very rarely causing HYPONATRAEMIA.
Sensitivity reactions are very rare, usually occurring in the ?rst six to eight weeks of therapy. They include transient rashes which rarely progress to erythema multiforme (see under ERYTHEMA) and exfoliate DERMATITIS, fever and jaundice; chlorpropamide may also occasionally result in photosensitivity. Rare blood disorders include THROMBOCYTOPENIA, AGRANULOCYTOSIS and aplastic ANAEMIA.
Biguanides Metformin, the only available member of this group, acts by reducing GLUCONEOGENESIS and by increasing peripheral utilisation of glucose. It can act only if there is some residual insulin activity, hence it is only of value in the treatment of non-insulin dependent (type 2) diabetics. It may be used alone or with a sulphonylurea, and is indicated when strict dieting and sulphonylurea treatment have failed to control the diabetes. It is particularly valuable in overweight patients, in whom it may be used ?rst. Metformin has several advantages: hypoglycaemia is not usually a problem; weight gain is uncommon; and plasma insulin levels are lowered. Gastrointestinal side-effects are initially common and persistent in some patients, especially when high doses are being taken. Lactic acidosis is a rarely seen hazard occurring in patients with renal impairment, in whom metformin should not be used.
Other antidiabetics Acarbose is an inhibitor of intestinal alpha glucosidases (enzymes that process GLUCOSIDES), delaying the digestion of starch and sucrose, and hence the increase in blood glucose concentrations after a meal containing carbohydrate. It has been introduced for the treatment of type 2 patients inadequately controlled by diet or diet with oral hypoglycaemics.
Guar gum, if taken in adequate doses, acts by delaying carbohydrate absorption, and therefore reducing the postprandial blood glucose levels. It is also used to relieve symptoms of the DUMPING SYNDROME.... hypoglycaemic agents
Low blood sugar. It can be an actual clinical condition (rather rare), but the term is usually applied to LABILE blood sugar, where the highs are socially acceptable, if zappy, but the lows cause headaches, depression...and sugar cravings...which only kick the sugars UP...which forces the sugars DOWN...etc. This is a subclinical condition that usually goes nowhere, at least clinically, but can drive you (or your companion) crazy. Some normal and healthy food have a rapid blood presence and can leave you hanging; fruits, potatoes and carrot juice are LOUSY...legumes, particularly beans, supply slow and extended release of calories...mostly because of high levels of soluble fiber...and laborious digestion. Even adding such dietarily useless items like Psyllium Seed and Chia Seed can do wonders to slow down sugar spiking.... hypoglycemia
Having either low secretion levels of testosterone by the testes, having low functional effects because of poor circulation, having competition by less active testosterone metabolites, or having high levels of adipose-released estradiol (former testosterone) in obesity that ends up suppressing testosterone. There are, of course, organic diseases that can cause the condition.... hypotestosteronism
Having deficient thyroid levels, either from overt thyroid disease like myxedema, a generally low metabolism from functional causes, or subsequent to emotional depression or the use of depressant drugs.... hypothyroid
A supposition that appears to explain a group of phenomena and is advanced as a basis for further investigation; a proposition that is subject to proof or to an experimental or statistical test. Studies are often framed to test a ‘null’ hypothesis (for example “subjects will experience no change in blood pressure as a result of administration of a test product”) to rule out every possibility except the one the researcher is trying to prove, an assumption about a research population that may or may not be rejected as a result of testing. A null hypothesis is used because most statistical methods are less able to prove something true than to provide strong evidence it is false. See also “theory”; “null hypothesis”.... hypothesis
Broadly the accumulative process of emotional and metabolic evaluation, as carried on by the various parts of the brain that are part of the ad hoc “evaluations” committee (the limbic system) and those changes in metabolism that, based on the evaluations, are acted out in the whole body by the hypothalamus. The hypothalamus, the main part of the system with tools, acts through a blood translator, the pituitary gland.... limbic/hypothalamus
corresponds to a large extent with what used to be known as ‘secondary anaemia’. It takes its name from the characteristic changes in the blood.... microcytic hypochromic anaemia
Some excipients used in the manufacture of tablets may have an allergenic effect. They may include additives, colourings, yeast, iodine, etc to which an increasing number of people are allergic. Present-day tablet-makers move away from these chemical binders and fillers, using natural alternatives such as vegetable oils, calcium phosphate, acacia gum and alginic acid from seaweeds. The term also refers to products, including herbal preparations made without sugar, starch, salt, wheat, yeast or artificial preservatives: suitable for vegetarians. ... hypo-allergenic
A rare deficiency of the hormone aldosterone, which is produced by the adrenal glands. The condition may be caused by damage or disease affecting the adrenal glands. It may produce weakness, and is treated by the drug fludrocortisone.... hypoaldosteronism
the theory that *schizophrenia is caused in part by abnormalities in the metabolism of *dopamine and can be treated in part by drugs that antagonize its action as a neurotransmitter.... dopamine hypothesis
n. subnormal activity of the *adrenal glands, which can be due to disease of the adrenal glands themselves (e.g. *Addison’s disease) or to a lack of stimulation from the pituitary hormone *ACTH as part of any condition causing *hypopituitarism.... hypoadrenalism
n. a condition in which the sense of touch is diminished; uncommonly this may be extended to include other forms of sensation.... hypoaesthesia
adj. at a pressure lower than that of the atmosphere.... hypobaric
n. the presence in the blood of an abnormally low concentration of chloride.... hypochloraemia
n. a recently discovered neuropeptide that originates in the hypothalamus. Low levels of hypocretin in the cerebrospinal fluid are found in most patients with *narcolepsy and may also be found in patients who have suffered with stroke, brain tumours, head injuries, and infections of the nervous system.... hypocretin
n. a genus of non-bloodsucking beelike insects – the warble flies – widely distributed in Europe, North America, and Asia. Cattle are the usual hosts for the parasitic maggots, but rare and accidental infections of humans have occurred (see myiasis), especially in farm workers. The maggots migrate beneath the skin surface, producing an inflamed linear lesion similar to that of *creeping eruption.... hypoderma
n. pathological failure to drink enough to maintain the body’s normal plasma osmolality. Like its most extreme form, adipsia, it is most commonly due to lesions of the thirst centre in the anterior hypothalamus.... hypodipsia
n. congenital absence of one or more teeth (not including the third molars, whose absence is considered a normal variation). Forms of hypodontia include *oligodontia and *anodontia.... hypodontia
adj. (in ultrasound imaging) describing a darker area, which is usually caused by any structure (e.g. a cyst) that allows the sound waves to pass through and therefore reflects echoes to a lesser degree than the adjacent structure. Compare hyperechoic.... hypoechoic
n. that part of the central *abdomen situated below the region of the stomach. —hypogastric adj.... hypogastrium
(fibrinogenopenia) n. a deficiency of the clotting factor *fibrinogen in the blood, which results in an increased tendency to bleed. It may occur as an inherited disorder in which either production of fibrinogen is impaired or the fibrinogen produced does not function in the normal way (dysfibrinogenaemia). Alternatively, it may be acquired. For example, it is the commonest cause of blood coagulation failure during pregnancy, when the blood fibrinogen level falls below the normal pregnancy level of 4–6 g/l as a result of *disseminated intravascular coagulation (DIC). This usually occurs as a complication of severe *abruptio placentae, prolonged retention of a dead fetus, or amniotic fluid embolism.... hypofibrinogenaemia
n. a condition in which the sense of taste is abnormally weak. See also hypoaesthesia.... hypogeusia
a serious condition in which a person with diabetes loses the earliest warning signs of an approaching hypoglycaemic episode. Such people may suffer a severe attack of hypoglycaemia, with confusion, seizures, or even coma and death, because they fail to take the necessary measures to abort the episode. The condition is more common in longstanding diabetes and in those who experience frequent hypoglycaemic episodes. People with hypoglycaemic unawareness should not drive. Some awareness of hypoglycaemia may be restored by careful avoidance of more episodes, ensuring that the blood glucose level never falls below 4 mmol/l.... hypoglycaemic unawareness
n. a deficiency of insulin due either to inadequate secretion of the hormone by the pancreas or to inadequate treatment of diabetes mellitus.... hypoinsulinism
adj. (in CT scanning) describing a structure or substance (e.g. gas) that is less dense than surrounding structures (allows more X-rays to pass through) and therefore appears darker on CT. Compare hyperintense.... hypointense
abnormalities seen with chronic hypokalaemia (usually K+ <3.0 mmol/l) and manifest by impaired urine-concentrating ability and reduced capacity to excrete sodium. Histological changes include cytoplasmic vacuolation of the renal tubules and medullary fibrosis.... hypokalaemic nephropathy
(laryngopharynx) n. the part of the pharynx that lies below the level of the hyoid bone.... hypopharynx
n. a rare condition of inflammation of the *pituitary gland (hypophysis). The main cause is an infiltration by lymphocytes, most commonly during or just after pregnancy. This usually presents as a mass lesion of the pituitary with visual-field loss and headache or with anterior *hypopituitarism, which may be total or just involve particular hormone systems. Around 50% of cases are associated with other autoimmune endocrine diseases, and antipituitary antibodies have been identified.... hypophysitis
a congenital heart disorder in which the left side of the heart, particularly the left ventricle, is underdeveloped. The first part of the aorta may also be abnormal. Affected babies usually develop severe heart failure within the first few days of life. Diagnosis can be confirmed on *echocardiography. Prognosis is generally very poor – most babies die within the first few weeks – but milder cases may be amenable to surgery. It is the commonest cause of death in the neonatal period due to heart disease.... hypoplastic left heart
a stage of *leukaemia in which there is a decrease in the number of white cells, red cells, and platelets in the blood and reduced *haemopoiesis in the bone marrow.... hypoplastic leukaemia
n. an episode during sleep in which there is a reduction in the nasal airflow to less than 50% of normal, but more than 30% (see apnoea), for more than 10 seconds. See also obstructive sleep apnoea.... hypopnoea
n. pus in the anterior chamber (in front of the iris) of the eye. Seen in severe cases of *uveitis or other ocular infections, it can be a sign of endophthalmitis following intraocular surgery.... hypopyon
adj. less than normally responsive to the presence of antigenic material. Compare hypersensitive. —hyposensitivity n.... hyposensitive
n. reduction in the sense of smell. See anosmia.... hyposmia
n. a state of physical weakness or abnormally low muscular tension.... hyposthenia
n. the secretion of urine of low specific gravity. The inability to concentrate the urine occurs in patients at the final stage of chronic renal failure.... hyposthenuria
adj. describing or relating to the fleshy prominent part of the palm of the hand below the little finger. Compare thenar.... hypothenar
see imperative.... hypothetical imperative
n. a very low intraocular pressure, usually as a result of trauma or surgery to the eye.... hypotony
n. a condition in which less hair develops than normal.... hypotrichosis
n. see strabismus.... hypotropia
(HIE, birth asphyxia, perinatal asphyxia) brain damage in a newborn infant as a result of the brain receiving inadequate oxygen. HIE may cause seizures and, if severe, death within minutes of oxygen deprivation. If the infant survives there can be significant long-term consequences, such as developmental delay, learning disabilities, or cerebral palsy.... hypoxic-ischaemic encephalopathy
an increasingly recognized type of persistent headache in a patient with no history of headaches. Features include headache that is worse on standing and resolves on lying flat. It may be associated with other symptoms, such as dizziness, tinnitus, and (rarely) *diplopia. The commonest cause is a complication of lumbar puncture, but it may occur spontaneously (spontaneous intracranial hypotension) after a dural tear resulting in a leak of cerebrospinal fluid. Treatment is with bed rest and increased intake of fluids; caffeine orally or intravenously is also used. In cases that do not resolve, an epidural blood patch procedure is performed, in which a small quantity of the patient’s blood is slowly injected into the *epidural space to seal the leak.... intracranial hypotension headache
the hypothesis that gene dosage imbalance between males and females, because of the presence of two X chromosomes in females (XX) as opposed to only one in males (XY), is compensated for by random inactivation of one of the X chromosomes in the somatic cells of females. The inactivated X chromosome becomes the Barr body (see sex chromatin). [M. F. Lyon (1925–2014), British geneticist]... lyon hypothesis
a defect involving a deficiency in the mineralization of permanent first molar and incisor teeth during their maturation phase, thought to be due to a disturbance of development around the time of birth. It often presents in discolouration (yellow, brown, cream, or white depending on severity) and results in the affected teeth being more susceptible to decay.... molar–incisor hypomineralization
(oral antihyperglycaemic drug) one of the group of drugs that reduce the level of glucose in the blood and are taken by mouth for the treatment of type 2 *diabetes mellitus. They include the *sulphonylurea group (e.g. glibenclamide, gliclazide), metformin (a *biguanide), *alpha-glucosidase inhibitors, *meglitinides, *thiazolidinediones, *DPP-IV inhibitors, and *SGLT-2 inhibitors.... oral hypoglycaemic drug
a condition of postprandial *hypoglycaemia, of varying severity, induced by excessive levels of insulin release from the pancreas. It can be divided into early and late forms, depending on whether the insulin release occurs less than or more than three hours after the meal. The early form is due to the rapid discharge of ingested carbohydrate from the stomach into the small bowel, immediately triggering hyperinsulinaemia. It can occur without obvious cause but is most commonly associated with upper-bowel surgery. The late form is due to a loss of the early-phase insulin response causing excessive postprandial *hyperglycaemia, which then itself triggers an exaggerated insulin response with subsequent hypoglycaemia.... reactive hypoglycaemia
see intracranial hypotension headache.... spontaneous intracranial hypotension
see aortocaval compression.... supine hypotension
lowering the cholesterol content of the blood.... hypocholesterolaemia
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