| Meaning | ||
| h | hr / hours | |
| H | histamine or its receptors (if with subscripts) hemagglutinin | |
| Hx | history | |
| HA ;H/A | hypertonia arterialis headache calcium hydroxyapatite | |
| HAA | hepatitis-associated antigen or #History As Above | |
| HAART | highly active antiretroviral therapy | |
| HACA | human anti-chimeric antibody | |
| HACE | High-altitude cerebral edema | |
| acronym for a group of bacteria that are a frequent cause of endocarditis in children | ||
| HAD | HIV-associated dementia | |
| HADS | Hospital Anxiety and Depression Scale | |
| HAE | hereditary angioedema | |
| H/A | headache | |
| HAI | healthcare-associated infection or hospital-acquired infection | |
| HALE | health-adjusted life expectancy | |
| HAPE | high-altitude pulmonary edema | |
| HAV | hepatitis A virus | |
| Hb | hemoglobin | |
| HB | heart block | |
| Hb% | hemoglobin concentration in gram per deciliter | |
| HbA | hemoglobin A (commonest type of hemoglobin) | |
| HbA1c | glycated hemoglobin (used as a measure of diabetes control) | |
| HBD | has been drinking | |
| HbF | fetal hemoglobin | |
| HBO | hyperbaric oxygen | |
| HBP | high blood pressure, that is, hypertension | |
| HbsAg | Hepatitis B surface antigen | |
| HBV | hepatitis B virus | |
| HC | head circumference hemorrhagic colitis homocysteine | |
| HCA | Healthcare Associated, as in HCA-CDI | |
| HCAP | health care-associated (or acquired) pneumonia | |
| HCC | hepatocellular carcinoma | |
| HCF | Healthcare Facility | |
| HCFA | Healthcare Facility Associated, as in HCFA-CDI | |
| hCG | human chorionic gonadotropin | |
| HCL | hairy cell leukemia | |
| HCM | hypertrophic cardiomyopathy healthcare maintenance | |
| HCO3 | bicarbonate | |
| Hct | hematocrit | |
| HCT | hematocrit hematopoietic cell transplantation | |
| HCRP | Hospital Cornea Retrieval Programme | |
| HCTZ | hydrochlorothiazide | |
| HCV | hepatitis C virus | |
| HD | Hodgkin disease Hemodialysis Huntington's disease | |
| HDL | high-density lipoprotein | |
| HDL-C | high-density lipoprotein-cholesterol | |
| HDN | hemolytic disease of the newborn | |
| HDS | hemodynamically stable (i.e., not bleeding) | |
| HDU | high dependency unit | |
| HDV | hepatitis D virus | |
| HDW | Hemoglobin Distribution Width | |
| H&E | hematoxylin and eosin, a standard tissue stain | |
| HE | hepatic encephalopathy | |
| HEC | High emetogenic chemotherapy | |
| HEENT | head, eyes, ears, nose, throat | |
| HELP HELLP | HELLP syndrome (Hemolysis, elevated liver enzymes, low platelets in pregnancy) | |
| HEMA | hydroxy ethyl methacrylate, a material in soft contact lenses | |
| Hema | hematest – e.g. hema (-) – fecal occult blood | |
| HES | hydroxyethyl starch | |
| HETE | hydroxyeicosatetraenoic acid | |
| HEV | hepatitis E virus | |
| HF | heart failure | |
| HFpEF | heart failure with preserved ejection fraction | |
| HFrEF | heart failure with reduced ejection fraction | |
| HFM | hand, foot and mouth disease | |
| HFMD | hand, foot and mouth disease | |
| HFNC | high flow Nasal cannula | |
| HFRS | hemorrhagic fever with renal syndrome | |
| HGB | hemoglobin | |
| HGH | Human Growth Hormone | |
| HGSIL | high-grade squamous intraepithelial lesion | |
| HGV | hepatitis G virus | |
| HGPRTase | hypoxanthine-guanine phosphoribosyl transferase | |
| HH | hemihypertrophy hiatus hernia hitting head | |
| H/H or H&H | hemoglobin and hematocrit | |
| HHS | Hyperosmolar hyperglycemic state | |
| HHT | hereditary hemorrhagic telangiectisia | |
| HHV | human herpesvirus (including numerous subtypes such as HHV8) | |
| HI | homicidal ideation | |
| Hib | haemophilus influenzae B | |
| HIDA | hepatobiliary iminodiacetic acid | |
| HIDS | hyper-IgD (and periodic fever) syndrome | |
| HIE | hypoxic ischemic encephalopathy (cerebral hypoxia) | |
| HIT | heparin-induced thrombocytopenia | |
| HIV | human immunodeficiency virus | |
| HL | hepatic lipase Hodgkin's lymphoma hearing level | |
| HLA | human leukocyte antigen | |
| HLD | Hyperlipidemia | |
| HLHS | hypoplastic left heart syndrome | |
| H&M | hematemesis and melena | |
| HMD | ||
| HMG | human menopausal gonadotropin | |
| HMG-CoA | 3-hydroxy-3-methyl-glutaryl-CoA | |
| HMGR | 3-hydroxy-3-methyl-glutaryl-CoA reductase | |
| H-mole | hydatidiform mole | |
| HMS | hyperreactive malarial splenomegaly | |
| HMSN | hereditary motor sensory neuropathy | |
| HN | hemagglutinin-neuraminidase | |
| HND | hemolytic disease of the newborn | |
| HNP | spinal disk herniation or herniated disk, that is, herniated nucleus pulposus | |
| HNPCC | hereditary nonpolyposis colorectal cancer | |
| HNPP | hereditary neuropathy with liability to pressure palsy | |
| H/O | history of ... | |
| HOB | head of bed (usually followed by number of degrees of elevation, e.g., HOB 10°) | |
| HOCM | hypertrophic obstructive cardiomyopathy | |
| HONK | hyperosmolar nonketotic state | |
| HOPI | History of present illness | |
| H&P | history and physical examination (which very often are considered as a pair) | |
| HPA | ||
| HPETE | hydroxyeicosatetraenoic acid | |
| HPF | high-power field (microscopy) | |
| HPI H/oPI | history of the present illness | |
| HPOA | hypertrophic pulmonary osteoarthropathy (clubbing) | |
| hPL | human placental lactogen (same as human chorionic somatomammotropin) | |
| HPP | hypokalemic periodic paralysis | |
| HPS | hantavirus pulmonary syndrome | |
| HPV | human papillomavirus | |
| HR | heart rate | |
| hr | hour or hours | |
| HRS | Hepatorenal syndrome | |
| HRAS | Harvey rat sarcoma viral oncogene homolog | |
| HRCT | High-resolution computed tomography | |
| HRT | hormone replacement therapy | |
| h.s. | at bedtime (from Latin hora somni) | |
| hs | hours of sleep | |
| H→S | heel-to-shin test | |
| HSC | human chorionic somatomammotropin (same as human placental lactogen) | |
| HSCT | Hematopoietic stem cell transplantation | |
| HSG | hysterosalpingogram | |
| HSIL | high-grade squamous intraepithelial lesion | |
| HSM | hepatosplenomegaly | |
| - | HSP | Henoch–Schönlein purpura |
| HSV | herpes simplex virus | |
| HT | hypertension | |
| Ht | height | |
| HTLV | human T-lymphotropic virus | |
| HTN | hypertension | |
| HTPA | ||
| HTVD | hypertensive vascular disease | |
| HUS | hemolytic uremic syndrome | |
| HVA | homovanillic acid | |
| HVLT | high-velocity lead therapy (facetious term for gunshot wound) | |
| Hx | history (of) |