| NREH | normal renin essential hypertension |
|---|---|
| OHI | Occupational Health Institute; operative hypertension indicator; oral hygiene index; Oral Hygiene In... |
| OHT | ocular hypertension |
| OPH | obliterative pulmonary hypertension; ophthalmia |
| PAH | para-aminohippurate; phenylalanine hydrolase; polycyclic aromatic hydrocarbon; predicted adult heigh... |