| HASHD | hypertensive arteriosclerotic heart disease |
|---|---|
| HASP | Hospital Admissions and Surveillance Program |
| HASS | highest anxiety subscale score |
| HAT | Halsted Aphasia Test; head, arm, trunk; heparin-associated thrombocytopenia; heterophil antibody titer; hospital arrival time; hypoxanthine, aminopterin, and thymidine; hypoxanthine, azaserine, and thymidine |
| HATG | horse antihuman thymocyte globulin |
| HATH | Heterosexual Attitudes Toward Homosexuality [scale] |
| HATT | heparin-associated thrombocytopenia and thrombosis |
| HATTS | hemagglutination treponemal test for syphilis |
| HAU | hemagglutinating unit |
| HAV | Hepatitis A Virus |