Basics

Many parts of Mexico, especially popular tourist areas, are visited safely, but safety varies by state. Check the current US State Department advisories.

Period cramps occur when the uterus contracts to shed its lining, triggered by hormone-like chemicals called prostaglandins. The cause Before and during

Eyes sting when crying because tears contain salt and other substances that irritate the surface of the eye. Why it stings Tears contain salt, which irritates

Dreaming about an ex usually reflects unresolved feelings, nostalgia, or stress, and does not necessarily mean you want them back. Common reasons Unresolved

Dogs scratch their beds to make them comfortable, a leftover nesting instinct, and to mark them with scent. Reasons Nesting instinct: wild dogs scratched

Weakness can come from poor sleep, dehydration, low blood sugar, anemia, or infection. See a doctor if it persists. Common causes Poor sleep or overexertion.

Nuclear power plants split uranium atoms (fission) to heat water into steam, which spins a turbine to generate electricity. Fission Nuclear power plants

Memorial Day honors those who died in military service, while Veterans Day honors everyone who has served. Memorial Day The last Monday of May.

Broiling uses intense direct heat from above, while baking uses moderate heat that surrounds the food. Baking Cooks with surrounding hot air at 300 to 450 F.

Corns are small, hard, often painful bumps with a core on the toes or feet, while calluses are wider, thicker, usually painless patches of hard skin.