Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Your thumb is about the same size as your nose.
124
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
Your heart will pump about 212 million liters in its lifetime.
26
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
One human hair can support 3 ounces.
191
Chewing gum boosts your brain power.
285
Every year your body replaces 98% of your atoms.
119