(S)
Sanguineous crust - Scab
Scarlatina - Scarlet fever
Scarlet fever - A disease characterized by red rash
Scarlet rash - Roseola
Sciatica - Rheumatism in the hips
Scirrhus - Cancerous tumors
Scotomy - Dizziness, nausea and dimness of sight
Scrivener's palsy - Writer's cramp
Screws - Rheumatism
Scrofula - Tuberculosis of neck lymph glands. Progresses slowly with abscesses and pistulas develop. Young person's disease
Scrumpox - Skin disease, impetigo
Scurvy - Lack of vitamin C. Symptoms of weakness, spongy gums and hemorrhages under skin
Septicemia - Blood poisoning
Shakes - Delirium tremens
Shaking - Chills, ague
Shingles - Viral disease with skin blisters
Ship fever - Typhus
Siriasis - Inflammation of the brain due to sun exposure
Sloes - Milk sickness
Small pox - Contagious disease with fever and blisters
Softening of brain - Result of stroke or hemorrhage in the brain, with an end result of the tissue softening in that area
Sore throat distemper - Diphtheria or quinsy
Spanish influenza - Epidemic influenza
Spasms - Sudden involuntary contraction of muscle or group of muscles, like a convulsion
Spina bifida - Deformity of spine
Spotted fever - Either typhus or meningitis
Sprue - Tropical disease characterized by intestinal disorders and sore throat
St. Anthony's fire - Also erysipelas, but named so because of affected skin areas are bright red in appearance
St. Vitas dance - Ceaseless occurrence of rapid complex jerking movements performed involuntary
Stomatitis - Inflammation of the mouth
Stranger's fever - Yellow fever
Strangery - Rupture
Sudor anglicus - Sweating sickness
Summer complaint - Diarrhea, usually in infants caused by spoiled milk
Sunstroke - Uncontrolled elevation of body temperature due to environment heat. Lack of sodium in the body is a predisposing cause
Swamp sickness - Could be malaria, typhoid or encephalitis
Sweating sickness - Infectious and fatal disease common to UK in 15th century