• Hand-foot-and-mouth disease
• Head lice
• Headaches and migraines
• Heart attack (myocardial infarction)
• Heart failure
• Heat stroke
• Hemorrhoids
• Hepatitis C
• Herniated disc
• Herpes labialis (cold sores)
• Herpes zoster (shingles)
• High blood cholesterol
• HIV
• Hives (urticaria)
• Hypertension
• Hypoglycemia
• Hypotension
• Hypothyroidism