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
Poor eyesight (myopia) is associated with higher IQ.
232
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
Your thumb is about the same size as your nose.
124
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22