Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
The human brain doesn't stop developing until about 25 years old.
102