MAO monoamine oxidase
MAP mean arterial pressure
MAST medical antishock trousers
MBT maternal blood type
MCH mean cell hemoglobin
MCHC mean cell hemoglobin concentration
MCV mean cell volume
MI myocardial infarction or mitral insufficiency
mL milliliter
MLE midline episiotomy
MMEF maximal mid expiratory flow
mmol millimole
MMR measles, mumps, rubella
mo months old
MRI magnetic resonance imaging
MRSA methicillin resistant staph aureus
MS multiple sclerosis or mitral stenosis, or morphine sulfate
MSSA methicillin-sensitive staph aureus
MVA motor vehicle accident
MVI multivitamin injection
MVV maximum voluntary ventilation