O
Objective
O2
Oxygen
OA
Osteoarthritis
OB
Obstetrics
OB/GYN
Obstetrics and gymocology
obl.
Oblique
OBS
Organic brain syndrome
obstr
Obstruction
occ
Occasionally
OD
Overdose
OHU
Open heart unit
oint.
Ointment
OM
Otitis media
OOB
Out of bed
OP
Out patient
OPG
Ocular pneumoplethysomograph
opth.
Ophthalmology
OR
Operating Room
ORIF
Open reduction internal fixation
ortho.
Orthopedics
OVR
Office of vocational rehabilitation
/p
After post
P
Poor muscle pulse plan