Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Enamel is hardest substance in the human body.
61
An Indian man known as "Snake Manu" can put small snakes, including deadly cobras, into his mouth and pass them out through his nose.
59
If your DNA was stretched out it would reach to the moon 6,000 times.
256
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92