Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
If your DNA was stretched out it would reach to the moon 6,000 times.
256
Poor eyesight (myopia) is associated with higher IQ.
232
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
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197