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
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
Your body is creating and killing about 2.4 million red blood cells per second.
17
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
Your thumb is about the same size as your nose.
124
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
Poor eyesight (myopia) is associated with higher IQ.
232