Mayo Clinic specialists answer health questions from readers like you.

• Salt craving: A symptom of Addison's disease?
• Salty taste in mouth: What causes it?
• Scalp psoriasis vs. seborrheic dermatitis: How are they different?
• Scar cream: Does it work?
• Schamberg's disease
• Schizoaffective disorder
• Schizophrenia and drug abuse: Are they related?
• Scrotum discomfort: Why is my husband always 'adjusting' himself?
• Sea salt and kosher salt: Are they better for you than regular salt?
• Seasonale side effects: Is breakthrough bleeding a concern?
• Sedation dentistry: Relief for dental anxiety?
• Sedimentation rate (sed rate): What does it mean?
• Selenium supplements: Do they increase my diabetes risk?
• Semen allergy
• Senior dating: Resuming sexual activity later in life
• Senior exercise: Am I too old for strength training?
• Separated shoulder
• Separation anxiety in preschooler: Is this normal?
• Septo-optic dysplasia
• Sesamoiditis treatment: Is surgery an option?
• Shaken baby syndrome: What are the signs and symptoms?
• Sheehan's syndrome
• Shift work: How do I adjust to daytime sleeping?
• Shingles vaccine: Can I transmit the vaccine virus to others?
• Shingles vaccine: Who should get it?
• Sickle cell anemia: Will a warmer climate help?
• Silicone breast implants: What happens if they rupture?
• Sinus infection toothache: Can sinus problems cause tooth pain?
• Sinusitis treatment: Can over-the-counter drugs help?
• Sit-ups: Is it OK to stabilize my feet?
• Sjogren's syndrome: Can it cause recurrent UTIs?
• Skin tag removal: Can I do it myself?
• Sleep aids: Can antihistamines help me sleep?
• Sleep and health: How many hours of sleep are enough?
• Sleep apnea in young children
• Sleep deprivation: Can it cause high blood pressure?
• Slow metabolism: Is there any such thing?
• Small cell lung cancer: Can brain radiation prevent spread?
• Small cell, large cell: What do these cancer classifications mean?
• Smart Balance: Are cholesterol-lowering products safe for everyone?
• Smoking: How does it affect your skin?
• Soy: Does it affect hypothyroidism?
• Soy: Does it reduce cholesterol?
• Spastic colon: What does it mean?
• Speech delays: When to be concerned
• Sperm: How long do they live after ejaculation?
• Spider veins: Do they increase the risk of blood clots?
• Spina bifida and childbirth: Can I have an epidural?
• Spiriva side effects: Is stomach upset a concern?
• Split fingernails: What causes them?
• Sprained ankle: Can you overdo compression wraps?
• Stargardt's disease: Can it be treated?
• Statin drugs: Can they cause memory problems?
• Statin side effects: Can they lower libido?
• Statins: Any link to amyotrophic lateral sclerosis (ALS)?
• Stevens-Johnson syndrome
• Stevia: Is it available in the United States?
• Stickler's syndrome
• Stiff-person syndrome: Can it be treated?
• Stomach flu: How long am I contagious?
• Stomach noise: What makes my stomach growl?
• Stool color: When to worry
• Strength training: How many sets for best results?
• Strength training: Tired of the same old routine? Mix it up
• Strep C: A concern in humans?
• Strep throat in infants: Is this common?
• Stress and hair loss: Are they related?
• Stress: Can it make you fat?
• Stretch marks: How do you get rid of them?
• Stridor: What is it?
• Stroke-related dementia: Can it be mistaken for Alzheimer's?
• Stuttering in children: Is it normal?
• Subacute thyroiditis (viral thyroiditis)
• Sudden hearing loss: What causes it?
• Sudden infant death syndrome: New guidelines for prevention
• Sugar: Does it cause ADHD?
• Sulfa allergy: Which medications should I avoid?
• Sun allergy: Can you be allergic to the sun?
• Sun exposure: Can it help fight cancer?
• Sunburn treatment: What works?
• Suncreen labels: What does "PA" mean?
• Sundowning: Late-day confusion
• Sunlight: How much do I need?
• Sunscreen use: Does it increase breast cancer risk?
• Superior vena cava syndrome
• Superslow strength training: Does it work?
• Swallowing gum: Is it harmful?
• Swimmers' itch: What causes it?
• Swollen lymph nodes (lymphadenitis)
• Swollen testicle: A cause for concern?
• Synovial osteochondromatosis: What causes it?
• Syringomyelia: What are the causes?