Diagnosaurus
- S1, loud
- S2, fixed split
- S2, paradoxically split or no split
- S2, widely split
- S3
- S4
- Sacroiliitis
- Saddle nose
- Salivary gland tumor
- Scaly lesions
- Scleritis or episcleritis
- Scrotal mass or swelling
- Scrotal pain
- Scrotal rash
- Seborrheic dermatitis
- Seizure
- Seizure in HIV/AIDS
- Sepsis
- Septal perforation
- Sexual dysfunction, men
- Sexual intercourse, painful
- Shock
- Shortness of breath
- Shoulder pain
- Shunt (right to left, anatomic shunts)
- Singultus
- Sinopulmonary syndromes
- Sinusitis, acute
- Sinusitis, chronic
- Sinus tachycardia
- Skin metastases
- Skin nodules and arthritis
- Sleep, abnormal behaviors
- Sleep apnea
- Sleepiness, excessive
- Sleeping difficulty
- Smell, abnormal sense of
- Sneezing
- Sodium, decreased serum
- Sodium, increased serum
- Somatoform disorder
- Sore throat
- Sore throat and rash
- Spasticity
- Spells (nonspecific)
- Spinal cord metastases
- Spinal cord tumor
- Splenomegaly
- Splinter hemorrhages
- Spotting, midcycle
- ST depression or T wave inversion
- ST elevation, EKG
- Stiff neck
- Stiffness
- Stool, black tarry
- Stool, bloody
- Stress disorder
- Stridor
- Subcutaneous nodules
- Sudden death
- Swallowing, painful
- Swallowing difficulty
- Sweating, excessive
- Syncope
- Systolic murmur