Human health and medicine

Hemiparkinsonism-hemiatrophy syndrome

Hemiparkinsonism-hemiatrophy syndrome (HPHA, HP-HA syndrome) is a rare parkinsonian disorder with unilateral body atrophy and ipsilateral bradykinesia, rigidity, and tremor, onset in adolescence or adulthood, prevalence under 1 per million, and variable levodopa response.

Hemipelvectomy

Hemipelvectomy, also called external hemipelvectomy or hindquarter amputation, is surgery removing an entire leg with part of the pelvis, usually for malignant bone or soft-tissue tumors.

Oct 20, 2026

Hemiplegia

Hemiplegia is severe or complete paralysis of one side of the body (ICD-11 MB53), usually from brain or spinal cord injury such as stroke; distinguished from hemiparesis (partial weakness), with flaccid and spastic forms.

Hemispatial neglect

Hemispatial neglect, also called unilateral spatial neglect or hemineglect, is a post-stroke attention disorder in which patients ignore the side of space opposite a brain lesion, usually the left after right hemisphere stroke.

Hemispherectomy

Hemispherectomy: neurosurgical removal or disconnection of one cerebral hemisphere to treat drug-resistant epilepsy. Includes anatomic hemispherectomy, functional hemispherectomy, and hemispherotomy; about 73% pooled seizure freedom, hydrocephalus the main complication.

Hemispherotomy

Hemispherotomy is a neurosurgical operation that disconnects one cerebral hemisphere from the rest of the brain to stop drug-resistant epilepsy, most often in children with extensive disease confined to that hemisphere.

Hemithyroidectomy

Hemithyroidectomy is an operation removing one lobe of the thyroid gland, usually with the isthmus, leaving the opposite lobe, parathyroids, and recurrent laryngeal nerve intact.

Hemoadsorption

Hemoadsorption is an extracorporeal blood purification therapy in which blood passes through a cartridge of adsorbent beads to remove inflammatory mediators, endotoxin, or toxins, aiming to moderate sepsis, drug toxicity, and poisoning.

HEMOBOX study

HEMOBOX (NCT03863652) is a prospective multicenter observational study of 250 patients measuring hemostasis duration after PCI via the distal radial snuffbox approach, reporting mean 199 minutes, 99.2% success, and no radial artery occlusion.

Hemodiafiltration

Hemodiafiltration is a kidney-failure blood-purification treatment combining the diffusive solute removal of hemodialysis with the convective removal of hemofiltration, clearing middle molecules and lowering mortality in randomized trials.

Hemodialysis

Hemodialysis filters wastes, extra salt, and water from blood through a dialyzer for kidney failure; in-center three times weekly or home schedules; access via AV fistula, graft, or catheter; invented by Willem Kolff in 1943.

Hemodilution

Hemodilution is the deliberate dilution of a patient's blood to reduce transfusions. In acute normovolemic hemodilution, blood is withdrawn after anesthesia and reinfused after surgery.

Hemodynamic assessment of pulmonary hypertension

Hemodynamic assessment of pulmonary hypertension is the measurement of pressures in the lungs' arteries, chiefly by right-heart catheterization, to diagnose pulmonary hypertension and classify it as pre- or post-capillary.

Hemodynamic monitoring

Hemodynamic monitoring is the measurement of circulatory variables, chiefly blood pressure and cardiac output, to guide treatment in critically ill patients, using tools from cuff pressure to invasive catheters.

Hemofiltration

Hemofiltration, also called CAVH or CVVH in continuous form, is a convective renal replacement technique removing water and middle molecules across a permeable membrane with replacement fluid; first performed by Peter Kramer in 1977 in Göttingen.

Hemoglobin Bart's fetalis syndrome

Hemoglobin Bart's fetalis syndrome, also called hemoglobin Bart's hydrops fetalis or alpha-thalassemia major, is the most severe form of alpha-thalassemia, caused by deletion of all four alpha globin genes and usually fatal without intrauterine transfusions.

Hemoglobin C

Hemoglobin C (HbC, HBB Glu6Lys) is a beta-globin variant causing red cell dehydration and crystals. HbAC trait is asymptomatic; HbCC causes mild anemia; HbSC is sickle cell disease with prominent retinopathy.

Hemoglobin C disease

Hemoglobin C disease (HbCC) is an autosomal recessive hemoglobinopathy from a beta-globin Glu6Lys mutation, causing mild hemolytic anemia, splenomegaly, and gallstones with normal life expectancy; distinct from HbC trait and HbSC disease.

Hemoglobin C-beta-thalassemia syndrome

Hemoglobin C-beta-thalassemia (HbC-BT, C-beta-thalassemia) is a compound heterozygous hemoglobinopathy combining HbC and a beta-thalassemia mutation, causing mild to moderate microcytic hemolytic anemia with splenomegaly, mainly in people of African descent.

Hemoglobin D disease

Hemoglobin D disease (Hb D-Punjab, Hb D-Los Angeles) is a beta-globin variant (β121 Glu→Gln, HBB c.364G>C) common in Punjab, India; benign alone, severe with Hb S.

Hemoglobin E

Hemoglobin E (HbE, Glu26Lys, HBB c.79G>A) is a common Asian beta-globin variant that is both a structural hemoglobin change and a mild beta-thalassemia mutation; HbE/β-thalassemia causes about half of severe beta thalassemia.

Hemoglobin E disease

Hemoglobin E disease (Hb EE), a benign hemoglobinopathy from a codon 26 beta-globin mutation common in Southeast Asia; trait is asymptomatic, but Hb E/beta-thalassemia causes about half of severe beta-thalassemia worldwide.

Hemoglobin E-beta-thalassemia syndrome

Hemoglobin E-beta-thalassemia (HbE-BT, E-beta-thalassemia) is an autosomal recessive beta-thalassemia of compound heterozygotes for HbE and beta-thalassemia, predominant in Southeast Asia, ranging from mild intermedia-like anemia to thalassemia major.

Hemoglobin electrophoresis

Hemoglobin electrophoresis is a blood test that separates and measures hemoglobin types (HbA, HbA2, HbF, HbS, HbC, HbE) by electric charge to diagnose sickle cell disease, thalassemia, and other hemoglobinopathies.

Hemoglobin H disease

Hemoglobin H disease (HbH disease, alpha-thalassemia intermedia): inherited anemia from inactivation of three of four alpha-globin genes; excess beta chains form unstable HbH tetramers; non-deletional forms are more severe.

Hemoglobin M disease

Hemoglobin M disease (M hemoglobinopathy; methemoglobinemia, beta type) is an autosomal dominant congenital methemoglobinemia from His-to-Tyr globin variants (Hb M-Boston, M-Iwate, M-Saskatoon, M-Milwaukee) causing benign lifelong cyanosis needing no treatment.

Hemoglobin variants

Hemoglobin variants, also called Hb variants, are abnormal forms of hemoglobin produced by globin gene mutations; more than 1000 are known, some causing erythrocytosis or cyanosis.

Oct 20, 2026

Hemoglobinometry

Hemoglobinometry (haemoglobinometry): measurement of blood hemoglobin concentration to screen and diagnose anemia. Cyanmethemoglobin method and automated analyzers are reference standards; HemoCue dominates point-of-care field testing; WHO 2024 guidance favors venous blood.

Hemolysis

Hemolysis is premature red blood cell destruction with hemoglobin release, causing hemolytic anemia; covers intravascular vs extravascular mechanisms, lab markers (haptoglobin, LDH, DAT), hereditary and immune causes, complement inhibitors, and 2023 sickle cell gene therapies.