| NIHS | National Institute of Hypertension Studies |
|---|---|
| NREH | normal renin essential hypertension |
| OHI | Occupational Health Institute; operative hypertension indicator; oral hygiene index; Oral Hygiene In... |
| OHT | ocular hypertension |
| PIH | periventricular-intraventricular hemorrhage; phenyl isopropylhydrazine; pregnancy-induced hypertensi... |