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 your DNA was stretched out it would reach to the moon 6,000 times.
256
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217