| 1. | Salivary Gland Diseases (40 studies) |
| 2. | Salivary Gland Neoplasms (25 studies) |
| 3. | Salmonella Infections (1 study) |
| 4. | Sarcodina Infections (1 study) |
| 5. | Sarcoidosis (9 studies) |
| 6. | Sarcoidosis, Pulmonary (1 study) |
| 7. | Sarcoma (301 studies) |
| 8. | Sarcoma, Alveolar Soft Part (10 studies) |
| 9. | Sarcoma, Clear Cell (8 studies) |
| 10. | Sarcoma, Endometrial Stromal (10 studies) |
| 11. | Sarcoma, Ewing's (73 studies) |
| 12. | Sarcoma, Kaposi (88 studies) |
| 13. | Sarcoma, Synovial (23 studies) |
| 14. | Sarcomastigophora Infections (7 studies) |
| 15. | Schizophrenia (104 studies) |
| 16. | Schizophrenia and Disorders with Psychotic Features (99 studies) |
| 17. | Schizophrenia, Childhood (1 study) |
| 18. | Sciatic Neuropathy (4 studies) |
| 19. | Sciatica (4 studies) |
| 20. | Scleral Diseases (1 study) |
| 21. | Scleritis (1 study) |
| 22. | Scleroderma, Localized (8 studies) |
| 23. | Scleroderma, Systemic (18 studies) |
| 24. | Sclerosis (95 studies) |
| 25. | Scoliosis (1 study) |
| 26. | Seasonal Affective Disorder (7 studies) |
| 27. | Sebaceous Gland Diseases (1 study) |
| 28. | Secernentea Infections (2 studies) |
| 29. | Secondary Acute Myeloid Leukemia (139 studies) |
| 30. | Seizures (40 studies) |
| 31. | Self-Injurious Behavior (4 studies) |
| 32. | Seminoma (26 studies) |
| 33. | Sensation Disorders (38 studies) |
| 34. | Sepsis (30 studies) |
| 35. | Sepsis Syndrome (2 studies) |
| 36. | Septicemia (30 studies) |
| 37. | Serotonin Syndrome (10 studies) |
| 38. | Severe Acute Respiratory Syndrome (2 studies) |
| 39. | Severe Combined Immunodeficiency (11 studies) |
| 40. | Sex Chromosome Disorders (10 studies) |
| 41. | Sex Differentiation Disorders (9 studies) |
| 42. | Sex Disorders (3 studies) |
| 43. | Sexual and Gender Disorders (3 studies) |
| 44. | Sexual Dysfunctions, Psychological (3 studies) |
| 45. | Sexually Transmitted Diseases (1508 studies) |
| 46. | Sexually Transmitted Diseases, Bacterial (8 studies) |
| 47. | Sexually Transmitted Diseases, Viral (1499 studies) |
| 48. | Sezary Syndrome (114 studies) |
| 49. | Shock (13 studies) |
| 50. | Shock, Cardiogenic (2 studies) |
| 51. | Shock, Hemorrhagic (1 study) |
| 52. | Shock, Septic (6 studies) |
| 53. | Short Bowel Syndrome (2 studies) |
| 54. | Shoulder Pain (1 study) |
| 55. | Shprintzen Syndrome (2 studies) |
| 56. | Shwachman Syndrome (3 studies) |
| 57. | Shy-Drager Syndrome (1 study) |
| 58. | Sick Sinus Syndrome (1 study) |
| 59. | Sickle Cell Trait (2 studies) |
| 60. | Sigmoid Diseases (2 studies) |
| 61. | Sigmoid Neoplasms (2 studies) |
| 62. | Signs and Symptoms (1081 studies) |
| 63. | Signs and Symptoms, Digestive (54 studies) |
| 64. | Signs and Symptoms, Respiratory (9 studies) |
| 65. | Silicosis (1 study) |
| 66. | Sinusitis (4 studies) |
| 67. | Sitosterolemia (6 studies) |
| 68. | Situs Inversus (1 study) |
| 69. | Sjogren's Syndrome (12 studies) |
| 70. | Skin Abnormalities (15 studies) |
| 71. | Skin and Connective Tissue Diseases (386 studies) |
| 72. | Skin Diseases (240 studies) |
| 73. | Skin Diseases, Bacterial (7 studies) |
| 74. | Skin Diseases, Eczematous (2 studies) |
| 75. | Skin Diseases, Genetic (23 studies) |
| 76. | Skin Diseases, Infectious (48 studies) |
| 77. | Skin Diseases, Metabolic (30 studies) |
| 78. | Skin Diseases, Papulosquamous (25 studies) |
| 79. | Skin Diseases, Parasitic (3 studies) |
| 80. | Skin Diseases, Vascular (11 studies) |
| 81. | Skin Diseases, Vesiculobullous (7 studies) |
| 82. | Skin Diseases, Viral (32 studies) |
| 83. | Skin Manifestations (3 studies) |
| 84. | Skin Neoplasms (178 studies) |
| 85. | Skin Ulcer (17 studies) |
| 86. | Skull Neoplasms (26 studies) |
| 87. | Sleep Apnea Syndromes (35 studies) |
| 88. | Sleep Apnea, Obstructive (6 studies) |
| 89. | Sleep Deprivation (4 studies) |
| 90. | Sleep Disorders (60 studies) |
| 91. | Sleep Disorders, Circadian Rhythm (2 studies) |
| 92. | Sleep Disorders, Intrinsic (52 studies) |
| 93. | Sleep Initiation and Maintenance Disorders (11 studies) |
| 94. | Slow Virus Diseases (67 studies) |
| 95. | Smallpox (20 studies) |
| 96. | Smith-Lemli-Opitz Syndrome (6 studies) |
| 97. | Smith-Magenis Syndrome (2 studies) |
| 98. | Smoking (34 studies) |
| 99. | Soft Tissue Infections (1 study) |
| 100. | Soft Tissue Neoplasms (23 studies) |
| 101. | Somatoform Disorders (2 studies) |
| 102. | Somatosensory Disorders (3 studies) |
| 103. | Somatostatinoma (19 studies) |
| 104. | Spasm (7 studies) |
| 105. | Spasmodic Dysphonia (7 studies) |
| 106. | Spasms, Infantile (2 studies) |
| 107. | Spastic Dysphonia (7 studies) |
| 108. | Spastic Paraplegia, Hereditary (1 study) |
| 109. | Speech Disorders (11 studies) |
| 110. | Sphingolipidoses (33 studies) |
| 111. | Spinal and Bulbar Muscular Atrophy (1 study) |
| 112. | Spinal Cord Diseases (70 studies) |
| 113. | Spinal Cord Injuries (29 studies) |
| 114. | Spinal Cord Neoplasms (10 studies) |
| 115. | Spinal Diseases (24 studies) |
| 116. | Spinal Dysraphism (2 studies) |
| 117. | Spinal Fractures (2 studies) |
| 118. | Spinal Injuries (1 study) |
| 119. | Spinal Neoplasms (1 study) |
| 120. | Spinal Stenosis (5 studies) |
| 121. | Spinocerebellar Degenerations (6 studies) |
| 122. | Spirochaetales Infections (10 studies) |
| 123. | Spirurida Infections (1 study) |
| 124. | Splenic Diseases (5 studies) |
| 125. | Splenomegaly (3 studies) |
| 126. | Spondylarthritis (17 studies) |
| 127. | Spondylarthropathies (17 studies) |
| 128. | Spondylitis (8 studies) |
| 129. | Spondylitis, Ankylosing (8 studies) |
| 130. | Spondylolisthesis (4 studies) |
| 131. | Sporotrichosis (3 studies) |
| 132. | Sprains and Strains (6 studies) |
| 133. | Staphylococcal Infections (5 studies) |
| 134. | Staphylococcal Skin Infections (2 studies) |
| 135. | Stargardt's Disease (2 studies) |
| 136. | Status Epilepticus (1 study) |
| 137. | Stereotypic Movement Disorder (2 studies) |
| 138. | Stickler Syndrome (1 study) |
| 139. | Stiff-Person Syndrome (3 studies) |
| 140. | Still's Disease, Adult-Onset (1 study) |
| 141. | Stomach Diseases (100 studies) |
| 142. | Stomach Neoplasms (91 studies) |
| 143. | Stomatitis (6 studies) |
| 144. | Stomatitis, Aphthous (3 studies) |
| 145. | Stomatognathic Diseases (213 studies) |
| 146. | Stomatognathic System Abnormalities (5 studies) |
| 147. | Strabismus (10 studies) |
| 148. | Streptococcal Infections (7 studies) |
| 149. | Stress (63 studies) |
| 150. | Stress Disorders, Post-Traumatic (29 studies) |
| 151. | Stress Disorders, Traumatic (29 studies) |
| 152. | Stress Disorders, Traumatic, Acute (2 studies) |
| 153. | Strongyloidiasis (1 study) |
| 154. | Sturge-Weber Syndrome (21 studies) |
| 155. | Stuttering (7 studies) |
| 156. | Subarachnoid Hemorrhage (3 studies) |
| 157. | Substance Abuse, Intravenous (4 studies) |
| 158. | Substance Withdrawal Syndrome (5 studies) |
| 159. | Substance-Related Disorders (303 studies) |
| 160. | Sudden Infant Death (2 studies) |
| 161. | Suicide (8 studies) |
| 162. | Suicide, Attempted (3 studies) |
| 163. | Suppuration (12 studies) |
| 164. | Supranuclear Palsy, Progressive (2 studies) |
| 165. | Supratentorial Neoplasms (6 studies) |
| 166. | Surgical Wound Infection (1 study) |
| 167. | Sweat Gland Diseases (1 study) |
| 168. | Syncope (7 studies) |
| 169. | Syncope, Vasovagal (3 studies) |
| 170. | Syndactyly (2 studies) |
| 171. | Syndrome X (9 studies) |
| 172. | Synostosis (2 studies) |
| 173. | Synovitis (6 studies) |
| 174. | Syphilis (3 studies) |
| 175. | Syringomyelia (3 studies) |
