72,234 articles
Haemolytic uraemic syndrome
Haemolytic uraemic syndrome (Gasser syndrome, ICD-11 3A21.2), a thrombotic microangiopathy with thrombocytopenia, hemolytic anemia, and kidney injury; usually Shiga toxin E. coli, sometimes complement-mediated aHUS.
Haemonchus contortus
Haemonchus contortus, the barber's pole worm, is a blood-feeding abomasal nematode of sheep and goats causing anemia; its resistance to all major anthelmintic drug classes makes it widely studied.
Haemoperitoneum
Haemoperitoneum (hemoperitoneum, intraperitoneal hemorrhage) is blood accumulating in the peritoneal cavity from internal bleeding. Causes are traumatic (liver, spleen), spontaneous (ectopic pregnancy, ruptured aneurysm, ovarian cyst), or iatrogenic; ICD-10 K66.1, ICD-11 DC51.2.
Haemophilia
Haemophilia, an inherited X-linked bleeding disorder from factor VIII (haemophilia A) or factor IX (haemophilia B, Christmas disease) deficiency; affects about 1 in 5,000 male births, treated with factor replacement, emicizumab, and AAV gene therapy.
Haemophilia A
Haemophilia A (classic hemophilia) is an X-linked bleeding disorder from factor VIII deficiency, affecting about 1 in 5,000 male births. Treated with factor replacement, emicizumab, efanesoctocog alfa, and the AAV5 gene therapy Roctavian.
Haemophilia B
Haemophilia B, also called Christmas disease, is an X-linked factor IX deficiency from F9 gene mutations, causing bleeding; treated with factor IX replacement, extended half-life products, and the 2022 gene therapy Hemgenix.
Haemophilia in European royalty
Haemophilia in European royalty: the X-linked bleeding disorder spread from Queen Victoria, a carrier, through daughters Alice and Beatrice to the Russian, Spanish, and German royal houses; identified in 2009 as haemophilia B (F9 mutation).
Haemophilic arthropathy
Haemophilic arthropathy is a chronic joint disease caused by repeated joint bleeding in hemophilia, marked by synovitis and cartilage destruction, mainly in knees, ankles, and elbows.
Haemophilus
Haemophilus, genus of gram-negative, nonmotile Pasteurellaceae bacteria requiring X (heme) or V (NAD) factors; type species Haemophilus influenzae, with six capsular serotypes a-f, Hib vaccine, and 2026 genomic reclassification.
Haemophilus ducreyi
Haemophilus ducreyi, a fastidious Gram-negative coccobacillus, causes chancroid (painful genital ulcers) and, increasingly recognized, non-sexually transmitted leg ulcers in children in yaws-endemic regions.
Haemophilus influenzae
Haemophilus influenzae (Hib, NTHi) is a gram-negative coccobacillus of the human respiratory tract causing meningitis, pneumonia, and otitis media; type b disease fell over 99% after 1987 conjugate vaccines, while nontypeable disease rises.
Haemophilus parainfluenzae
Haemophilus parainfluenzae (Rivers 1922) is a fastidious Gram-negative coccobacillus, V-factor-dependent HACEK member and human oral/pharyngeal commensal carried by about 65% of people, occasionally causing endocarditis, sepsis, and meningitis.
Haemophilus parasuis
Haemophilus parasuis, now Glaesserella parasuis, is a Gram-negative NAD-dependent Pasteurellaceae bacterium of pigs; it colonizes the upper respiratory tract and causes Glasser's disease (polyserositis, arthritis, meningitis), with 15 serovars of differing virulence.
Haemorhous
Haemorhous (Swainson, 1837) is a genus of three North American finches in Fringillidae: House Finch, Purple Finch, and Cassin's Finch, formerly placed in Carpodacus and split off after molecular work showed Carpodacus was polyphyletic.
Haemorrhage from throat
Haemorrhage from throat (咽頭出血), ICD-11 code MD21, is bleeding from the throat classified under haemorrhage from respiratory passages, excluding haemoptysis (MD22); synonyms include pharyngeal and oropharyngeal haemorrhage.
Haemorrhage in early pregnancy
Haemorrhage in early pregnancy (ICD-11 JA40) is first-trimester vaginal bleeding, including threatened abortion. It affects about 25% of pregnancies; management includes progesterone for prior miscarriage and expectant care.
Haemorrhagic septicaemia
Haemorrhagic septicaemia (HS), a WOAH-listed pasteurellosis of cattle and water buffalo caused by Pasteurella multocida serotypes B:2 and E:2 (6:B, 6:E), acute and near-100% fatal, endemic in tropical Asia and Africa, peaking in monsoon season.
Haemorrhoids
Haemorrhoids (piles) are swollen, inflamed veins around the anus or lower rectum, external or internal. About 1 in 20 Americans are affected; treatment ranges from fiber and sitz baths to banding and hemorrhoidectomy.
Haemorrhoids in pregnancy
Haemorrhoids (piles) in pregnancy: swollen anal cushions causing pain, itching, and bleeding, affecting roughly 30-40% of pregnant women, mainly in the third trimester. Treated with fiber, fluids, sitz baths, and topical preparations; usually resolve postpartum.
Haemothorax
Haemothorax (hemothorax) is blood accumulating in the pleural space, usually from chest trauma. Chest tube drainage is first-line; thresholds of 500 ml, 1,500 ml/24 h, and early VATS for retained blood guide management.
Haemulidae
Haemulidae (grunts), family Gill 1885 of tropical percomorph fishes, synonym Pomadasyidae; about 19 genera and 137 species in Atlantic, Indian, and Pacific oceans, named for pharyngeal-jaw stridulatory grunts.
Hafnia
Hafnia (Hafnia alvei, Hafnia paralvei) is a genus of gram-negative, facultatively anaerobic, motile Enterobacterales rods from feces, soil, water, and dairy; an opportunistic human pathogen with intrinsic colistin resistance and cheesemaking uses.
Hafnia alvei
Hafnia alvei, a Gram-negative facultatively anaerobic rod of the Enterobacteriaceae and type species of genus Hafnia, sucrose-negative, VP-positive; found in clinical, food, and animal sources; intrinsically colistin-resistant.
Hagenia abyssinica
Hagenia abyssinica (kosso, African redwood), sole species of the monotypic Rosaceae genus Hagenia, is a dioecious Afromontane tree from Eritrea to Zambia whose dried female flowers are a traditional Ethiopian tapeworm remedy; IUCN Least Concern but endangered in Ethiopia.
Hagfish
Hagfishes, also known as slime eels, are eel-like deep-sea jawless vertebrates that scavenge on dead fish and repel predators with slime that clogs their gills.
Haggis
Haggis, Scotland's national dish: a pudding of sheep heart, lungs, and liver with oatmeal, suet, onion, and pepper, boiled in a stomach casing, central to Burns Night (25 January), banned in the US since 1971, with a vegetarian version since 1984.
Hagop M. Kantarjian
Hagop M. Kantarjian is a Lebanese-born hematologist-oncologist at MD Anderson Cancer Center, chair of its leukemia department from 1995 to 2025 and a critic of cancer drug prices.
Hagop S. Akiskal
Hagop S. Akiskal (1944–2021), Armenian-American psychiatrist at UCSD, creator of the bipolar spectrum concept, bipolar III/IV subtypes, and TEMPS affective temperaments; NIMH adviser 1990–1994, Journal of Affective Disorders editor.
Hai‐Hui Xue
Hai-Hui (Howard) Xue is an immunologist at Hackensack Meridian Health's Center for Discovery and Innovation who studies how TCF1 controls T cell identity and memory.
Hai‐Quan Mao
Hai-Quan Mao is a biomedical engineer and polymer chemist at Johns Hopkins University, known for nanomaterials delivering DNA, RNA, and protein therapeutics and for nanofiber scaffolds in regenerative medicine.