| SI | System of International Units (Systeme International D'unites) |
|---|---|
| AAMRS | automated ambulatory medical record system |
| ABO | abortion; absent bed occupancy; American Board of Orthodontists; blood group system consisting of gr... |
| ACCESS | Ambulatory Care Clinic Effectiveness Systems Study; automated cervical cell screening system |
| ACS | acrocallosal syndrome; acrocephalosyndactyly; acute chest syndrome; acute confusional state; Alcon C... |