| Abbreviation | Definition |
|---|---|
| GXT | graded exercise tolerance (Stress test) |
| H/H | hemoglobin/hematocrit |
| H/H | Henderson-Hasselbach equation |
| HA | HeadAche |
| HAA | Hepatitis-Associated Antigen |
| HAACP | Hazard Analysis and Critical Control Point |
| HAART | Highly Active Anti-Retroviral Therapy |
| HAART | Highly Active Antiretroviral Therapy – the name commonly given to combinations of anti-HIV drugs |
| HAART | Highly Active Antiretroviral Therapy the name commonly given to combinations of anti-HIV drugs |
| HAB(CFSAN) | Hazard Assessment Branch (CFSAN) |
| HAC | Health Administration Center |
| HAC | Health Advisory Committee |
| HACCP | Hazard Analysis & Critical Control Point |
| HACCP | Hazard Analysis Critical Control Point |
| HAD | Hospital Anxiety and Depression scale |
| HAI | Health Action International |
| HAM/TSP | HTLV-I-associated myelopathy / tropical spastic paraparesis |
| HARTS | Hoechst Adverse Reaction Terminology System |
| HAV | Hepatitis A Virus |
| HAZOP | HAZard and OPerability analysis |