| HOCM | high-osmolar contrast medium; hypertrophic obstructive cardiomyopathy |
|---|---|
| OAD | obstructive airway disease; organic anionic dye |
| OH | hydroxycorticosteroid; obstructive hypopnea; occipital horn; occupational health; occupational histo... |
| OLD | obstructive lung disease; orthochromatic leukodystrophy |
| PVOD | pulmonary vascular obstructive disease; pulmonary veno-occlusive disease |