| Abbreviation | Definition |
|---|---|
| S | Squint |
| S | Stumble |
| S&SX | Signs And Symptoms |
| S/P | Status Post |
| S/UIQ | Simplified Urinary Impact Questionnaire |
| S/W | spike-and-wave |
| S-1 | First Sacral Vertebra |
| S-2 | Second Sacral Vertebra |
| SA | Short Acting |
| SA | Slow Asphyxiation |
| SA | Substance Abuse |
| SA | Systemic Amyloidosis |
| S-A | Sinoatrial Node |
| sAA | salivary alpha amylase |
| SAA | Spinal Adhesive Arachnoiditis |
| SAAG | serum-ascites albumin gradient |
| SAB | Spontaneous abortion |
| SABE | SubAcute Bacterial Endocarditis |
| SAC | Sacral |
| SAC | Shortarm Cast |