O
O/E:
On examination
O2:
Oxygen
OA:
Osteoarthritis
OB-GYN:
Obstetrics and gynecology
OCD:
Obsessive-compulsive disorder
OD:
Right eye from Latin , oculus dexter
OD:
Overdose
od:
Everyday, usually regarded as once daily , from Latin , Omni die .Generally written in lower case
OGTT:
Oral glucose tolerance test
om:
Every morning , from the Latin , omni mane .Generally written in lower case
on:
Every night, from the Latin , omni nocte. Generally written in lower case
OP:
Outpatient department
OPPT:
Oriented to person place and time
OS:
Left eye from Latin , oculus sinister
OS:
Orthopedic surgery
OSA:
Obstructive sleep apnea
OSH:
Outside hospital
OTC:
Over-the-counter drug
OTD:
Out the door (discharged)
OTPP:
Oriented to time place and person
OU:
Both eyes , from Latin , oculi uterque