| AIS/MR | Alternative Intermediate Services for the Mentally Retarded |
|---|---|
| AISA | Acquired Idiopathic Sideroblastic Anemia = RARS |
| AISA | acquired idiopathic sideroblastic anemia |
| AIT | acute intensive treatment |
| AITP | autoimmune idiopathic thrombocytopenic purpura |
| AITT | arginine insulin tolerance test; augmented insulin tolerance test |
| AIU | absolute iodine uptake; antigen-inducing unit |
| AIUM | American Institute of Ultrasound in Medicine |
| AIVR | accelerated idioventricular rhythm |
| AIVV | anterior informal vertebral vein |