All articles A–Z
519,064 articles
Hypertensive emergency
Hypertensive emergency: blood pressure above 180/120 mm Hg with acute target-organ damage (stroke, heart failure, aortic dissection, renal failure), formerly called malignant hypertension; treated in the ICU with titratable IV drugs, reducing BP by no more than 25% in the first hour.
Hypertensive encephalopathy
Hypertensive encephalopathy (HE), closely related to PRES, is cerebral edema from severe hypertension exceeding autoregulation; treated by lowering mean arterial pressure 20-25%, with 10.4% annual mortality in a French cohort.
Hypertensive heart disease
Hypertensive heart disease, also called hypertensive cardiomyopathy, is heart damage from long-standing high blood pressure, ranging from left ventricular hypertrophy to heart failure and sudden death.
Hypertensive heart failure
Hypertensive heart failure is heart failure caused by chronic pressure overload from high blood pressure, spanning preserved through reduced ejection fraction; hypertension is heart failure's most prevalent risk factor.
Hypertensive kidney disease
Hypertensive kidney disease (hypertensive nephrosclerosis) is kidney damage from sustained high blood pressure, a leading cause of ESRD; managed with SBP <130 mm Hg, ACEi or ARB, SGLT2 inhibitors, and diuretics.
Hypertensive peristalsis
Hypertensive peristalsis, also called nutcracker esophagus, was a Chicago Classification esophageal motility diagnosis defined by mean DCI over 5,000 mmHg·s·cm; it was eliminated in CC v3.0 and discontinued in v4.0 for unclear clinical significance.
Hypertensive retinopathy
Hypertensive retinopathy, also called fundus hypertonicus, is damage to the retinal blood vessels caused by high blood pressure, producing narrowed arterioles, hemorrhages, and exudates; treatment is mainly blood pressure control.
Hypertensive urgency
Hypertensive urgency, now renamed severe hypertension by the 2025 AHA/ACC guideline, is BP above 180/120 mm Hg without acute organ damage; guidelines favor oral therapy, observation, and outpatient follow-up over urgent intravenous lowering.
Hypertext
Hypertext is computer text with links letting readers choose their own path, a term coined by Ted Nelson in 1963 that underlies the World Wide Web.
Hypertherm
Hypertherm, formerly Hypertherm Inc and now Hypertherm Associates, is an American manufacturer of plasma, laser, and waterjet cutting systems founded in 1968 in Hanover, New Hampshire.
Hyperthermia
Hyperthermia (Greek hyper + therme) is an unregulated rise in body temperature above the hypothalamic set point, culminating in heat stroke above 40 °C with CNS dysfunction, treated by rapid cooling; it also names deliberate heating of tumors to about 45 °C as an adjunct cancer therapy.
Hyperthermic intraperitoneal chemotherapy
Hyperthermic intraperitoneal chemotherapy (HIPEC) is a cancer treatment in which chemotherapy heated to 41–43 °C is circulated inside the abdomen after cytoreductive surgery, used for peritoneal metastases of colorectal, ovarian, gastric, and appendiceal cancers.
Hyperthermophile
Hyperthermophiles are archaea and bacteria growing optimally at 80°C or above, first isolated in 1981; they inhabit volcanic and hydrothermal habitats, reach 113°C, and supply thermostable industrial enzymes.
Hyperthymesia
Hyperthymesia, or Highly Superior Autobiographical Memory (HSAM), is a rare condition of automatic, date-triggered recall of personal events, first described in Jill Price ("AJ") by McGaugh's UC Irvine team in 2006.
Hyperthyroidism
Hyperthyroidism (overactive thyroid): the thyroid gland makes excess hormone, speeding body functions. Most common cause is Graves' disease (TSHR autoantibodies); treated with antithyroid drugs, radioiodine, or surgery; affects about 1 in 100 Americans.
Hypertonia
Hypertonia, also called spasticity or rigidity in its main forms, is abnormally increased resistance to passive limb movement caused by loss of supraspinal control of stretch reflexes, assessed clinically with Ashworth and Tardieu scales.
HyperTransport
HyperTransport (HT) is a bidirectional, packet-based chip interconnect standard developed by AMD and standardized by a consortium from 2001, used in Opteron systems and supercomputers.
Hypertrichosis
Hypertrichosis, also called werewolf syndrome, is excessive hair growth anywhere on the body, distinct from androgen-driven hirsutism. It is congenital or acquired, drug-induced or paraneoplastic, and treated by hair removal and eflornithine.
Hypertrichosis cubiti
Hypertrichosis cubiti (hairy elbows syndrome, MacDermot-Patton-Williams syndrome) is a rare congenital bilateral hypertrichosis of the elbow extensor surfaces, OMIM 139600, sometimes with short stature or Wiedemann-Steiner syndrome.
Hypertrichosis lanuginosa congenita
Hypertrichosis lanuginosa congenita (hypertrichosis universalis) is a rare autosomal dominant congenital disorder with 3-5 cm lanugo hair over the whole body except palms, soles, and mucosae, sometimes with dental, ocular, and other defects.
Hypertriglyceridemia
Hypertriglyceridemia (HTG): fasting triglycerides above 150 mg/dL. Classified mild to very severe; causes ASCVD risk and pancreatitis at ≥500–1000 mg/dL. Treated with lifestyle, fibrates, omega-3s, statins, and new APOC3 agents like olezarsen.
Hypertriton lifetime puzzle
The hypertriton lifetime puzzle is the disagreement between heavy-ion collision measurements of the hypertriton's lifetime, which range from values matching the free Λ hyperon down to roughly half of it.
Hypertrophic cardiomyopathy
Hypertrophic cardiomyopathy (HCM), also called idiopathic hypertrophic subaortic stenosis, is a genetic heart disease with unexplained left ventricular thickening, prevalence about 1 in 500, first modern description by Teare in 1958, and treated with beta blockers, mavacamten, myectomy, and ICDs.
Hypertrophic cardiomyopathy screening
Hypertrophic cardiomyopathy screening detects the genetic thickened-heart disease (HCM, about 1 in 500 people) in athletes and relatives using history, physical, ECG, echo, MRI, and genetic testing; ECG raises sensitivity from 15-40% to 87-100%.
Hypertrophic chondrocyte
Hypertrophic chondrocyte: terminally differentiating growth plate cartilage cell, marked by type X collagen and Runx2, that enlarges about 20-fold, mineralizes matrix, and drives cartilage-to-bone conversion via Ihh-PTHrP, VEGF, and MMP signaling.
Hypertrophic lichen planus
Hypertrophic lichen planus (lichen planus verrucous, lichen planus hypertrophicus) is a chronic lichen planus variant with thickened, pruritic, wart-like plaques on the lower legs of adults 50-75, histologically marked by eosinophils and rete-ridge-tip infiltrates, distinguishable from squamous cell carcinoma.
Hypertrophic olivary degeneration
Hypertrophic olivary degeneration (HOD), trans-synaptic degeneration of the inferior olivary nucleus after lesions of the Guillain-Mollaret triangle; T2-hyperintense olive hypertrophy on MRI, palatal tremor, no enhancement or diffusion restriction.
Hypertrophic osteoarthropathy
Hypertrophic osteoarthropathy (HOA, pachydermoperiostosis in primary form, Bamberger-Marie syndrome) is a syndrome of digital clubbing, periostosis, and joint effusions; 95-97% of cases are secondary, most often to non-small cell lung cancer.
Hypertrophic scar
Hypertrophic scar: raised, fibroproliferative scar confined to the original wound, unlike keloids. Appears 1–2 months post-injury, regresses after 6 months; treated with intralesional triamcinolone, 5-FU, silicone, pressure, or laser therapy.
Hypertrophic surgical scar
Hypertrophic surgical scar (ICD-11 EL50.1): a raised, red scar confined to the surgical incision, occurring in 30-50% of surgical wounds, treated with triamcinolone injections, silicone, pressure, and laser.