Life and health

Hemerobiidae

Hemerobiidae, brown lacewings (Latreille, 1802), a Neuroptera family of small predatory insects; about 560-591 species, forewings 4-12 mm, multiple radial veins from R1, all continents except Antarctica.

Hemianopsia

Hemianopsia is the loss of one half of the vertical visual field, usually caused by stroke, brain tumor, or traumatic brain injury, occurring in homonymous or heteronymous forms depending on where the visual pathways are damaged.

Hemiarthroplasty

Hemiarthroplasty is a hip operation that replaces the femoral head and neck with a prosthesis while leaving the socket untouched, used mainly for displaced femoral neck fractures in older adults.

Hemiazygos vein

The hemiazygos vein, also called the inferior hemiazygos vein, is an unpaired left-sided chest vein that drains the lower posterior chest and abdominal wall and empties into the azygos vein.

Hemibagrus nemurus

Hemibagrus nemurus, the Asian redtail catfish or baung (Bagrus nemurus, Mystus nemurus), is a large bagrid river catfish of the Mekong, Chao Phraya, Malay Peninsula, Sumatra, Java, and Borneo, reaching 65 cm, farmed commercially, IUCN Least Concern.

Hemiballism

Hemiballism (hemiballismus), the most severe form of chorea, causes violent one-sided flinging limb movements from contralateral basal ganglia lesions, classically the subthalamic nucleus though most lesions lie elsewhere; stroke and nonketotic hyperglycemia are leading causes.

Hemibody Irradiation

Hemibody irradiation (HBI), or half-body irradiation, is palliative radiotherapy treating half the body in one field for widespread bone metastases; standard 800 cGy lower and 600 cGy upper doses, about 80% pain response, largely abandoned after the 1990s.

Hemic neoplasia of bivalves

Hemic neoplasia, also called disseminated neoplasia, is a leukemia-like transmissible cancer of marine bivalves, spreading as living cancer cells through seawater and affecting at least 15 species worldwide.

Hemicellulose

Hemicellulose is a group of branched, non-cellulosic polysaccharides in plant cell walls that bind to cellulose and reinforce it, making up 20 to 35% of the wall and including xylans and xyloglucans.

Hemichordate

Hemichordata, a phylum of marine deuterostomes with two classes, Enteropneusta (acorn worms) and Pterobranchia, about 130 described species, sister to Echinodermata in Ambulacraria, tripartite proboscis-collar-trunk body with gill slits.

Hemichorea

Hemichorea, also called hemichorea-hemiballismus, is unilateral chorea on one side of the body, classically linked to contralateral subthalamic nucleus lesions but usually caused by stroke or non-ketotic hyperglycemia.

Hemichorea or hemiballismus

Hemichorea or hemiballismus (hemichorea-hemiballism, HCHB), ICD-11 8A01.2: unilateral involuntary choreic or flinging proximal movements from contralateral basal ganglia or subthalamic lesions, most often stroke or nonketotic hyperglycemia; treated with neuroleptics, tetrabenazine, or GPi-DBS.

Hemicolectomy

A hemicolectomy is an operation in which a segment of the colon is removed, most often to treat colon cancer, together with the mesentery and lymph nodes that drain it.

Hemiconvulsion-hemiplegia-epilepsy syndrome

Hemiconvulsion-hemiplegia-epilepsy syndrome (HHE, hemiplegia-hemiconvulsion-epilepsy syndrome) is a rare childhood epilepsy syndrome: febrile hemiclonic status epilepticus, immediate permanent hemiplegia, then drug-resistant focal epilepsy within about 3 years.

Hemicorporectomy

Hemicorporectomy, or translumbar amputation, is an ultra-radical surgery removing the lower half of the body at the lumbar spine, with aorta, vena cava, and spinal cord transection. About 79 cases reported; used for pelvic malignancy, osteomyelitis, and trauma.

Hemicrania continua

Hemicrania continua, a rare indomethacin-responsive trigeminal autonomic cephalalgia, causes continuous strictly unilateral headache with ipsilateral tearing, conjunctival injection, or agitation, diagnosed by ICHD-3 criteria and treated with indomethacin.

Hemidactylus

Hemidactylus (Oken, 1817) is a genus of over 165 gekkonid gecko species, the house geckos; includes commensal invaders H. frenatus, H. mabouia, H. turcicus, and island radiations on Socotra and Cape Verde.

Hemidystonia-hemiatrophy syndrome

Hemidystonia-hemiatrophy (HD-HA) syndrome, ORPHA:306741, ICD-10 G24.8: a rare dystonia with hemidystonia and ipsilateral hemiatrophy, usually after perinatal or infantile cerebral injury, stroke, or trauma; fewer than 1 per million.

Hemiepiphysiodesis

Hemiepiphysiodesis is a pediatric orthopedic technique that arrests growth on one side of a growth plate, letting the other side grow to straighten angular limb deformities in children.

Oct 20, 2026

Hemifacial hyperplasia

Hemifacial hyperplasia (hemifacial hypertrophy, facial hemihypertrophy, ORPHA:141145, OMIM 133900) is a rare congenital unilateral overgrowth of facial bone, soft tissue, and teeth, true or partial, isolated or syndromic, treated after growth ceases.

Hemifacial myohyperplasia

Hemifacial myohyperplasia (HFMH) is a rare congenital disorder of unilateral overgrowth of the facial muscles only, without bone or other organ involvement; neonatal onset, prevalence under 1 in 1,000,000, described as a syndrome by Lee et al. in 2001.

Hemifacial spasm

Hemifacial spasm (HFS), also called hemispasme facial, is a movement disorder of unilateral involuntary facial muscle contractions, usually from vascular compression of the facial nerve root exit zone; treated with botulinum toxin and curative microvascular decompression (~90% spasm freedom).

Hemihepatectomy

Hemihepatectomy, including right hemihepatectomy, is a major hepatobiliary operation that removes one half of the liver, right or left, along the Cantlie line, reserved mainly for malignant tumors.

Oct 20, 2026

Hemihyperplasia-multiple lipomatosis syndrome

Hemihyperplasia-multiple lipomatosis syndrome (HHML) is a rare PIK3CA-related overgrowth disorder with asymmetric nonprogressive hemihyperplasia, multiple recurrent lipomas, vascular malformations, and possible embryonal malignancy risk.

Hemilaminectomy

A hemilaminectomy is a spinal decompression procedure that removes bone on one side of a vertebral arch, used in dogs for disc extrusion and in humans for lumbar stenosis.

Hemileia vastatrix

Hemileia vastatrix, coffee leaf rust, is a basidiomycete rust fungus described by Berkeley and Broome in 1869 in Ceylon; it destroyed Ceylon's coffee industry, spread worldwide by 1985, and causes USD 1–2 billion annual losses.

Hemimandibulectomy

Hemimandibulectomy is the surgical removal of one half of the mandible, performed mainly for oral cancers that invade the jawbone, and usually requiring reconstruction, often with a free fibula flap.

Hemimegalencephaly

Hemimegalencephaly (unilateral megalencephaly) is a rare congenital brain malformation with overgrowth of one cerebral hemisphere, causing infantile drug-resistant epilepsy, hemiparesis, and developmental delay; caused by somatic PI3K-AKT-mTOR mutations and treated with hemispherectomy.