| SFEMG | single fiber electromyography |
|---|---|
| SI | International System of Units [Fr. le Systeme International d'Unites]; sacroiliac; saline infusion; ... |
| SID | single intradermal [test]; Society for Investigative Dermatology; sucrase-isomaltase deficiency; sud... |
| SIMA | single internal mammary artery |
| SIR | single isomorphous replacement; specific immune release; standardized incidence ratio; syndrome of i... |