| Abbreviation | Definition |
|---|---|
| AHA | Australian Healthcare Association |
| AHC | Anterior Horn Cell |
| AHCC | Active Hexose Correlated Compound |
| AHD | Arteriosclerotic Heart Disease |
| AHD | Attention Hyperactive Disorder |
| AHD | Autoimmune Hemolytic Disease |
| AHEM | Acute Hemorrhagic EncephaloMyelitis |
| AHF | AntiHemophilic Factor |
| AHG | AntiHemophilic Globulin factor |
| AHI | apnea-hypopnea index |
| AI | Aortic Insufficiency |
| AI | Artificial Insemination |
| AI | Atherogenic Index |
| AIA | Ability and Involuntary Action |
| AIB | Air Inside Bone |
| AICD | Automatic Implantable Cardiac Defibrillator |
| AID | activation-induced deaminase |
| AID | Acute Infectious Disease |
| AID | Amputee Identity Disorder |
| AID | Artificial Insemination by Donor |