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Hypericum perforatum
Hypericum perforatum (St. John's wort, Klamath weed) is a perennial Hypericaceae herb native from Europe to China and NW Africa, used for mild to moderate depression; extracts show efficacy near standard antidepressants but induce CYP3A4 and P-glycoprotein, causing major drug interactions.
Hyperinflation
Hyperinflation is extremely rapid inflation with monthly price increases above 50 percent, a threshold set by Philip Cagan in 1956; Hungary in 1946 was the worst episode.
Hyperinflation in the Weimar Republic
Hyperinflation in the Weimar Republic, also called German hyperinflation, was the collapse of the German mark, peaking at about 30,000 percent monthly inflation in October 1923.
Hyperinflation in Venezuela
Hyperinflation in Venezuela (Hiperinflación venezolana) was a period of extreme price increases that began in late 2017, peaked in 2018 and 2019, and ended in December 2021.
Hyperinflation in Yugoslavia
Hyperinflation in Yugoslavia was a 1992–1994 episode in Serbia and Montenegro, with monthly inflation peaking at 313 million percent in January 1994 before a currency reform ended it.
Hyperinflation in Zaire
Hyperinflation in Zaire was a period of extreme inflation in the central African country of Zaire, now the Democratic Republic of the Congo, between 1990 and 1996.
Hyperinflation in Zimbabwe
Hyperinflation in Zimbabwe was the period from March 2007 to November 2008 when monthly inflation peaked at an estimated 79.6 billion percent, the second-highest recorded rate in world history, ending with dollarization in 2009.
Hyperinsulinemia
Hyperinsulinemia is an increased concentration of insulin in the blood, most often a compensatory response to insulin resistance, and is linked to diabetes and cardiovascular disease.
Hyperinsulinism due to short chain 3-hydroxylacyl-CoA dehydrogenase deficiency
SCHAD deficiency (HADH-related hyperinsulinism, hyperinsulinemic hypoglycemia familial 4) is a rare autosomal recessive diazoxide-responsive congenital hyperinsulinism causing leucine-sensitive hypoglycemia without hyperammonemia, via loss of SCHAD's inhibition of GDH.
Hyperinsulinism-hyperammonemia syndrome
Hyperinsulinism-hyperammonemia (HI/HA, GDH-HI) syndrome: a dominant GLUD1 gain-of-function disorder causing leucine-sensitive hypoglycemia, chronic hyperammonemia, epilepsy, and diazoxide-responsive congenital hyperinsulinism.
Hyperintensity
Hyperintensity: MRI term for tissue brighter than a comparison structure on a given sequence; covers T1/T2/FLAIR signal causes, white matter hyperintensities, and clinical significance.
Hyperion (asteroid)
Hyperion is a moon of Saturn and the largest of its irregular, nonspherical moons. Discovered in 1848, it is known for its sponge-like, deeply cratered surface.
Hyperion (comics)
Hyperion (Mark Milton) is Marvel Comics' Superman analogue, created by Roy Thomas and Sal Buscema, first appearing as a Squadron Sinister villain in Avengers #69 (1969) and as the heroic Squadron Supreme leader in Avengers #85 (1971), with versions in Supreme Power and Hickman's Avengers.
Hyperion (Simmons novel)
Hyperion (1989) is Dan Simmons's Hugo Award-winning space opera, first of the four-book Hyperion Cantos. Seven pilgrims travel to the Time Tombs to face the Shrike, in a Canterbury Tales-style frame narrative.
Hyperion (Titan)
Hyperion (Ὑπερίων) is the first-generation Greek Titan of heavenly light, son of Uranus and Gaia, husband of Theia, and father of Helios, Selene, and Eos; Homer also uses his name as an epithet of the Sun himself.
Hyperion (tree)
Hyperion is a coast redwood (Sequoia sempervirens) in Redwood National Park, California, the world's tallest known living tree at 379.1 ft verified in 2006; its location is secret and closed to visitors.
Hyperion (Ὑπερίων)
Hyperion (Ὑπερίων), Greek Titan son of Uranus and Gaea, father by Theia of Helios, Selene, and Eos; in Homer a by-name of the sun-god himself, later used by Shakespeare, Keats, and for Saturn's seventh moon.
Hyperion Cantos
Hyperion Cantos: Dan Simmons's four-novel science fiction series (Hyperion 1989, The Fall of Hyperion 1990, Endymion 1995, The Rise of Endymion 1997), a Canterbury Tales-style space opera featuring the Hegemony, TechnoCore, Shrike, and Hugo-winning first volume.
Hyperion Data Center
Hyperion Data Center is a Meta artificial intelligence data center campus in Richland Parish, Louisiana, announced in 2024 at $10 billion and expanded in 2026 to more than $50 billion.
Hyperions Schicksalslied
Hyperions Schicksalslied ("Hyperion's Song of Fate") is a three-stanza poem by Friedrich Hölderlin, published in the second volume of his epistolary novel Hyperion in 1799, and best known as the text of Brahms's Schicksalslied.
Hyperkalaemia
Hyperkalaemia (hyperkalemia), elevated blood potassium above 5.5 mmol/l, caused by kidney disease, RAAS-inhibiting drugs, or excess intake; severe cases cause ECG changes, arrhythmia, and need calcium, insulin-glucose, salbutamol, dialysis, or binders.
Hyperkalemia
Hyperkalemia is abnormally high blood potassium, usually from impaired kidney excretion or drugs; defined as K+ ≥ 5.5 mmol/L (UKKA), graded mild to severe, treated with IV calcium, insulin-glucose, binders like SZC and patiromer, or dialysis.
Hyperkalemic periodic paralysis
Hyperkalemic periodic paralysis (Gamstorp disease, HyperPP) is a rare autosomal dominant SCN4A sodium channelopathy causing childhood-onset attacks of flaccid weakness with raised serum potassium, treated with carbohydrates, salbutamol, and diuretics.
Hyperkeratosis
Hyperkeratosis: thickening of the skin's stratum corneum from excess keratin or poor shedding; covers corns, calluses, keratosis pilaris, ichthyoses, psoriasis, actinic keratosis, and skin cancers.
Hyperkeratosis lenticularis perstans
Hyperkeratosis lenticularis perstans (Flegel disease, HLP, OMIM 144150) is a rare keratinization disorder with red-brown 1–5 mm scaly papules on the feet and lower legs, linked to SPTLC1 variants, lacking standard treatment.
Hyperlacrimation
Hyperlacrimation (ICD-11 9A10.3) is overflow of tears from excessive lacrimal gland secretion, caused by drugs, emotion, or trigeminal reflex irritation; distinct from epiphora, a drainage failure.
Hyperlens
A hyperlens is a curved optical device made of a hyperbolic metamaterial that images below the diffraction limit by converting evanescent waves into propagating ones.
Hyperlexia
Hyperlexia: precocious, self-taught word reading far exceeding comprehension, usually with autism (about 84% of cases); coined by Silberberg and Silberberg in 1967; not a standalone DSM-5 diagnosis; three described types.
Hyperlink
A hyperlink, also known as a web link, is a connection between two resources on the web, realized by embedding a URL in one page that points to another.
Hyperlipidemia
Hyperlipidemia (hypercholesterolemia, lipid disorder) is abnormally high blood lipids or lipoproteins. High LDL and triglycerides drive atherosclerosis; detected by lipid profile, treated with statins, ezetimibe, PCSK9 inhibitors.