@
At
ā
Before
abd
abdomen
ABG
Arterial blood gases
a.c. Or ac
Before meals
ad lib
As desired
adm
Admission or admitted
ADL
Activities of daily living
ABO
The main blood group system
AM, A.M, a.m
Morning
AMA
Against medical advice
amb
Ambulate or ambulatory
amt
Amount
ANST
After negative skin test
AP or ap
Apical pulse
A-P
Anterior-posterior
Approx
Approximately