| ARRS | American Roentgen Ray Society |
|---|---|
| ARSC | arylsulfatase C; Associate of the Royal Society of Chemistry |
| ARSPH | Associate of the Royal Society for the Promotion of Health |
| ASA | acetylsalicylic acid; active systemic anaphylaxis; Adams-Stokes attack; American Society of Anesthes... |
| ASAAD | American Society for the Advancement of Anesthesia in Dentistry |