Browse Medical Abbreviations

O oral; other; Oxygen (element); ovulation
O&E observation and examination
O&G obstetrics and gynecology
O&P ova and parasites
O-A occipital-atlas
o.d. once daily (omni die)
O.D. right eye (oculus dexter)
o.h. every hour (omni hora)
o.m. every morning (omni mane)
o.n. every night (omni nocte)
O.S. left eye (oculus sinister)
O/E on examination
O/R oral, rectal
O2 oxygen
O2Sat Oxygen saturation (percent)
O3 ozone; Omega-3
o: objective
OA osteoarthritis; osteoarthrosis; occiput anterior
OAE oto acoustic emissions
OB obstetrics; occult blood
OB+ occult blood positive
OB-Gyn obstetrics and gynecology
OB/GYN obstetrics/gynecology
OBS organic brain syndrome; obstetrics
OBS/OBD organic brain syndrome/organic brain disorder
obsd observed
obst obstruct, obstruction
OBT over-bed table
OBUS obstetrical ultrasound
OC oral contraceptive; osteocalcin; obstetrical conjugate; oleoresin capsicum; oral cavity
occ occasional
OCD obsessive compulsive disorder
OCG oral cholecystogram
OCL orthopedic cast for limb
OCP oral contraceptive pills
OCR ossicular chain reconstruction
OCT oxytocin challenge test
OD overdose; right eye (oculus dexter); Doctor of Optometry; optical density (equivalent to absorbance)
od every day (omnes dies)
ODD oppositional defiant disorder
ODT orally disintegrating tablet
OE otitis externa
OFC occipital-frontal circumference
OFTT organic failure to thrive
OG orogastric
OGD oesophagogastroduodenoscopy
OGT oral glucose tolerance (test)
OGTT oral glucose tolerance test
OH oral hygiene
OH- hydroxyl ion
OI opportunistic infection
OIC opioid-induced constipation
oint ointment
OL left eye (oculus laevus)
ol. oil
OLMC on-line medical control
OM osteomalacia; otitis media
OMB operational management board
OMD organic mental disorders
OME otitis media with effusion
OMFS oral and maxillofacial surgery
OMH office for migrant health
omn. hor. every hour
omn. noct. every night
OmPC outer membrane protein complex
ONS oncology nursing society
OoA Office on Aging
OOB out of bed; out of breath
OOH out of hospital
OOR out of room
OOT out of town
OP outpatient; operative; occiput posterior
OPA oropharyngeal airway; outpatient appointment
OPCAB off-pump coronary artery bypass surgery
OPD outpatient department
OPER outpatient with extended recovery
OPG oculoplethysmography
Oph ophthalmology
OPHEP Office of Public Health Emergency Preparedness (HHS)
OPHS office of public health and science
Ophth ophthalmology; ophthalmoscope
OPMS oropharyngeal motility study
opp opposite
OPQRST onset, provocation, quality, radiation, severity, time
OPROC outpatient procedure
OPT outpatient
opt optimal; optical
OPV oral polio vaccine
OR operating room
org organization
ORIF open reduction and internal fixation
ORL otorhinolaryngology
ORM operational risk management
ORR objective response rate
ORS oral rehydration solution
Orth orthopedics
Ortho orthopedics
OS left eye (oculus sinister)
os mouth; bone
Os Osmium (element)
OSA obstructive sleep apnea
OSCE objective structured clinical examination
OSD over bed side drainage
OSHA Occupational Safety and Health Administration
OSHC Office of Science and Health Coordination (OC)
OSR open septo-rhinoplasty
osteo osteo myelitis
OT occupational therapy; occupational therapist
OTC over the counter
OTFC oral transmucosal fentanyl citrate
oto otoscope
OTR registered occupational therapist
OU both eyes (oculi unitas); each eye; Orthodox Union (kosher food indicator)
OV office visit
OXT oxytocin
oz ounce