| S2 | Sit The F**k Down And Shut The F**k Up | - | NASA |
| SAS | Sick As Sh*t | - | NASA |
| SBA | Silver Bracelet Award - Patient Is A Prisoner Brought In Wearing Cuffs | - | NASA |
| SBI | Something Bad Inside E.g. Undiagnosed Cancer/unexpected Serious Condition Found When Performing Surgery | - | NASA |
| SBLEO | (pronounced S-B-Leo) Suicide By Law Enforcement Officer | - | NASA |
| SBOD | Stupid Bitch / Bastard On Drugs | - | NASA |
| SEP | Somebody Else's Problem (not To Be Confused With Sepsis) | - | NASA |
| SFS | Stinky Foot Syndrome (often Related To Homeless) | - | NASA |
| SFSF | Sphincter Factor Scale: 1 To 10 Scale Indicating Degree Of Bowel-loosening In Response To An Emergency | - | NASA |
| SHA | Ship His Ass (when Patients Refuse To Be Discharged). | - | NASA |
| SHAD | Syphilitic, Hypochondriac, Alcoholic Degenerate | - | NASA |
| SHPOS | Sub-Human Piece Of Sh*t | - | NASA |
| SHS | Sullen, Hostile, Stupid (often An Inner City Drug/alcohol Addict) | - | NASA |
| SIG | Stroppy Ignorant Girl | - | NASA |
| SIO | Sleeping It Off | - | NASA |
| SNUD | Sick Nigh Unto Death | - | NASA |
| SOB | Short Of Breath | - | NASA |
| SOB | Silly Old Bugger / B*stard / Bitch | - | NASA |
| SOB | Sitting Out Of Bed / Sitting On Bed | - | NASA |
| SOCMOB | Standing On Corner Minding Own Business (when Inexplicably Injured) | - | NASA |
| SODDI | Some Other Doctor Did It (when One Medic's Botched Jobs Must Be Put Right/answered For By Someone Else) | - | NASA |
| SOG | Sick Old Guy (male Version Of LOL (Little Old Lady)) | - | NASA |
| SPAK | Status Post Ass Kicking | - | NASA |
| SRI | Something Wrong Inside (undiagnosable Problem) | - | NASA |
| SSDD | Same Sh*t Different Day | - | NASA |
| SVRI | Something Very Wrong Inside (usually Terminal) | - | NASA |
| SWAG | Scientific Wild Ass Guess | - | NASA |
| SWI | Something Wrong Inside | - | NASA |
| SWW | Sick, Wet And Whiny (infant) | - | NASA |
| SYB | Save Your Breath (for Patients Who Don't Take Advice) | - | NASA |
