All articles starting with H
20,046 articles
Hypothermia
Hypothermia, also called accidental hypothermia, is an unintentional drop in core body temperature below 35 °C (95 °F). Classified mild, moderate, severe; causes shivering, confusion, arrhythmias; treated by rewarming, ECLS in arrest.
Hypothermia of newborn
Hypothermia of newborn (neonatal hypothermia, ICD-11 KD12): core temperature below 36.5°C in a newborn. Common worldwide, worsens mortality 28% per degree below 36.5°C at admission; prevented by drying, warming, skin-to-skin care, plastic wrap.
Hypothesis
A hypothesis (Greek: ὑπόθεσις) is a specific, tentative statement about natural phenomena, made before a scientific process, that guides what data are collected and is supported or refuted by evidence.
Hypothetical Axis victory in World War II
Hypothetical Axis victory in World War II: counterfactual scenario and alternate history premise in which Germany, Italy, and Japan win; covers plausibility debates, scenario types, and fiction from The Man in the High Castle to Fatherland.
Hypothetical Document Embeddings
Hypothetical Document Embeddings (HyDE) is a query-time retrieval technique, introduced in 2022, where a language model's hypothetical answer document is embedded instead of the raw query.
Hypothetical types of biochemistry
Hypothetical types of biochemistry, also called alternative biochemistry, propose life not based on carbon in water: silicon-based life, solvents like ammonia, methane, sulfuric acid, or liquid CO2, and oxygen-free CHN chemistry for worlds such as Titan.
Hypothetico-deductive model
The hypothetico-deductive model is an account of scientific method in which a scientist deduces predictions from a hypothesis and tests them, often presented as the scientific method.
Hypothyroidism
Hypothyroidism: deficiency of thyroid hormone, usually primary (Hashimoto thyroiditis or iodine deficiency). Marked by high TSH with low free T4; treated with levothyroxine ~1.6 µg/kg/day. Also called underactive thyroid.
Hypotonia
Hypotonia (decreased muscle tone, floppy infant syndrome) is abnormally low resistance to passive movement, distinct from weakness. Causes are central (60-80% of neonatal cases) or peripheral neuromuscular; evaluation uses clinical signs and targeted testing.
Hypotonia-cystinuria syndrome
Hypotonia-cystinuria syndrome (HCS, OMIM 606407) is a rare autosomal recessive 2p21 contiguous gene deletion of SLC3A1 and PREPL causing neonatal hypotonia, cystinuria type 1, kidney stones, growth hormone deficiency, and hyperphagia in late childhood.
Hypotrichosis simplex
Hypotrichosis simplex, also known as hereditary hypotrichosis simplex, is a rare inherited hair-loss condition causing progressive thinning of scalp and body hair from childhood, with no other abnormalities.
Hypotrichosis simplex of the scalp
Hypotrichosis simplex of the scalp (HSS, OMIM 146520) is a rare autosomal dominant alopecia with normal hair at birth, progressive scalp-only hair loss from childhood, caused by nonsense CDSN mutations.
Hypotrichosis with juvenile macular degeneration
Hypotrichosis with juvenile macular degeneration (HJMD, OMIM 601553), a very rare autosomal recessive CDH3/P-cadherin disorder: sparse short hair from birth, progressive macular degeneration, blindness in the second to fourth decades; about 50 patients reported.
Hypotrichosis-deafness syndrome
Hypotrichosis-deafness syndrome, or hypotrichosis-hearing loss syndrome, is a rare autosomal dominant GJB2 (connexin 26) disorder with erythrokeratoderma, sparse hair, nail dystrophy, and sensorineural deafness.
Hypotrichosis-lymphedema-telangiectasia-renal defect syndrome
Hypotrichosis-lymphedema-telangiectasia-renal defect syndrome (HLTRS, OMIM 137940) is an ultra-rare SOX18-related lymphedema disorder with sparse hair, lower-limb lymphedema, palmar telangiectasia, and childhood renal failure, inherited dominantly or recessively.
Hypoventilation
Hypoventilation (respiratory depression, ventilatory failure): inadequate alveolar ventilation causing hypercapnia, from respiratory muscle weakness, chest wall disorders, obesity hypoventilation syndrome, or suppressed drive; treated with CPAP, NIV, or ventilation.
Hypovolaemic shock
Hypovolemic shock is a life-threatening condition in which loss of blood or plasma, most often from trauma or bleeding, leaves too little circulating volume for adequate tissue perfusion.
Hypovolemia
Hypovolaemia (hypovolemia), ICD-11 5C70.1, is decreased blood plasma volume from hemorrhage, burns, or fluid losses; severe cases cause hypovolemic shock treated with crystalloid resuscitation.
Hypovolemic shock
Hypovolemic shock: circulatory shock from critical intravascular volume loss (hemorrhage, GI, renal, or skin fluid losses), causing low preload and tissue hypoperfusion; treated with crystalloid or blood resuscitation and control of the source.
Hypoxanthine
Hypoxanthine, also called 6-hydroxypurine, is a purine nucleobase central to purine metabolism: it is the base of inosine, an intermediate in adenosine breakdown, and rises when cells are deprived of oxygen.
Hypoxanthine guanine phosphoribosyltransferase partial deficiency
Hypoxanthine guanine phosphoribosyltransferase partial deficiency (Kelley-Seegmiller syndrome, Lesch-Nyhan variant, OMIM 300323) is an X-linked HPRT1 disorder causing uric acid overproduction, gout, and variable neurological signs without self-injury.
Hypoxanthine-guanine phosphoribosyltransferase
Hypoxanthine phosphoribosyl transferase (HPRT, HGprt, EC 2.4.2.8), X-linked HPRT1 enzyme recycling hypoxanthine and guanine to IMP and GMP via PRPP; deficiency causes Lesch-Nyhan disease spectrum.
Hypoxemia
Hypoxemia: low partial pressure of oxygen in arterial blood (PaO2 < 60 mm Hg, SaO2 < 90%), distinct from tissue hypoxia. Five mechanisms: V/Q mismatch, shunt, diffusion limitation, hypoventilation, low inspired PO2.
Hypoxia (medicine)
Hypoxia (medicine): insufficient oxygen in body tissues, distinct from hypoxemia. Four types: hypoxemic, circulatory, anemic, histotoxic (cyanide). Detected by pulse oximetry and arterial blood gas; treated by addressing the cause.
Hypoxia in aviation
Hypoxia in aviation is a deficiency of oxygen that impairs normal function during flight, arising when cabin pressure falls, oxygen equipment fails, or blood oxygen carriage is reduced.
Hypromellose
Hypromellose, also called hydroxypropyl methylcellulose (HPMC), is a water-soluble cellulose ether that controls drug release in matrix tablets, lubricates artificial tears, and thickens food and cement mortars.
Hypromellose acetate succinate
Hypromellose acetate succinate (HPMCAS, Shin-Etsu AQOAT) is a cellulose-derived enteric pharmaceutical excipient, marketed since 1986, in L/M/H grades dissolving at pH 5.5/6.0/6.5, used for enteric coating and amorphous solid dispersions; GRAS notice GRN 960 closed 2021.
Hypselis
Hypselis, also known as Hypsele or Shashotep, was an ancient city in Upper Egypt, capital of the 11th nome and seat of the god Khnum, under modern Shutb.
Hypsithermal
The Hypsithermal, also known as the Altithermal or Holocene Climatic Optimum, was a warm interval of the mid-Holocene, about 9000 to 5000 years ago, caused by orbital forcing.
Hypsugo
Hypsugo (Savi's pipistrelle genus) is a genus of small vespertilionid bats in tribe Vespertilionini, type species Hypsugo savii, with roughly 16-18 species across the Palaearctic and Indo-Malayan regions, formerly often merged into Pipistrellus.