| Abbreviations | Meaning |
 | QMWS | Quasi-morphine Withdrawal Syndrome |
 | R-W | Rideal-Walker [coefficient]; Romano-Ward [syndrome] |
 | RADS | Reactive Airways Dysfunction Syndrome; Retrospective Assessment Of Drug Safety |
 | RALPH | Renal-anal-lung-polydactylyhamartoblastoma [syndrome] |
 | RASS | Rheumatoid Arthritis And Sjögren Syndrome |
 | RBAS | Rostral Basilar Artery Syndrome |
 | RBS | Random Blood Sugar; Receptor Binding Site; Remote [computer] Backup Service; Roberts Syndrome; Rutherford Backscattering |
 | RD | Riley-Day [syndrome] |
 | RD | Rolland-Desbuquois [syndrome] |
 | RDS | Respiratory Distress Syndrome |
 | RDS | Raskin Depression Scale; Respiratory Distress Syndrome; Reticuloendothelial Depressing Substance; Rhodanese; Slow Retinal Degeneration |
 | REAR | Renal, Ear, Anal, And Radial [malformation Syndrome] |
 | REAS | Reasonably Expected As Safe; Retained, Excluded Antrum Syndrome |
 | REEDS | Retention Of Tears, Ectrodactyly, Ectodermal Dysplasia, And Strange Hair, Skin And Teeth [syndrome] |
 | RGS | Regulation Of Ga Signaling; Rieger Syndrome |
 | RHE | Retinohepatoendocrinologic [syndrome] |
 | RHS | Ramsay Hunt Syndrome |
 | RHS | Rapp-Hodgkin Syndrome |
 | RHS | Reciprocal Hindlimb-scratching [syndrome] |
 | RHS | Richner-Hanhart Syndrome |
 | RKH | Rokitansky-Küster-Hauser [syndrome] |
 | RL | Renal Dysplasia-limb Defects [syndrome] |
 | RLS | Recursive Least Square; Restless Leg Syndrome; Ringer Lactate Solution; Roussy-Levy Syndrome; Run-length Statistics |
 | RMLS | Right Middle Lobe Syndrome |
 | RMS | Red Man Syndrome |
 | RMS | Repetitive Motion Syndrome |
 | RMS | Rigid Man Syndrome |
 | RMSS | Ruvalcaba-Myhre-Smith Syndrome |
 | ROW | Rendu-Osler-Weber [syndrome]; Rest Of The World |
 | ROXIS | Roxithromycin In Ischemic Syndromes [study] |
 | RRIS | Recurrent Respiratory Infection Syndrome |
 | RRS | Result Reporting [clinical Data] Repository System; Retrorectal Space; Richards-Rundle Syndrome |
 | RS | Richter's Syndrome (transformation Of CLL In DLCL) |
 | RS | Roberts Syndrome |
 | RS | Raynaud Syndrome |
 | RS | Reiter Syndrome |
 | RS | Rett Syndrome |
 | RS | Reye Syndrome |
 | RSDS | Reflex Sympathetic Dystrophy Syndrome |
 | RSS | Repetitive Stress Syndrome |
 | RSS | Russell-Silver Syndrome |
 | RSTS | Retropharyngeal Soft Tissue Space; Rubinstein-Taybi Syndrome |
 | RT | Rubinstein-Taybi (syndrome) |
 | RTS | Rett Syndrome |
 | RTS | Rothmund-Thomson Syndrome |
 | RTS | Rubinstein-Taybi Syndrome |
 | RW | Radiological Warfare; Ragweed; Respiratory Work; Romano-Ward [syndrome]; Round Window |
 | SADS | Sudden Arrhythmic Death Syndrome |
 | SAHA | Seborrhea-hypertrichosis/hirsutism-alopecia [syndrome] |
 | SAHIGES | Staphylococcus Aureus Hyperimmunoglobulinemia E Syndrome |