Medicine
- Artificial Heart Valve
- artificial kidney
- artificial life support
- artificial limb
- artificial respiration
- asepsis
- aspiration
- Aston-Patterning
- Atkins Diet
- ATLS
- audiology
- Audiometry
- Auditory integration training
- auscultation
- Autoradiography
- Autoscopy
- Aversion therapy
- Ayurvedic medicine
- balloon angioplasty
- Balloon dilatation