| HE | half-scan with extrapolation; hard exudate; hektoen enteric [agar]; hemagglutinating encephalomyelit... |
|---|---|
| HEI | Health Effects Institute; high-energy intermediate; homogenous enzyme immunoassay; human embryonic i... |
| HEIR | health effects of ionizing radiation; high-energy ionizing radiation |
| HEIS | high-energy ion scattering |
| HEPA | high-efficiency particulate air [filter] |