1.   Although a lot of what happens during sleep is not known, researchers do know that the body repairs itself.

2.   But if it progresses, patients may need breathing assistance and may remain hospitalized for months while their bodies repair damaged nerves.

3.   Furthermore, in people who smoked as adolescents, the body does not repair damaged DNA as well as those who began smoking at a later age.

4.   With rest, the body repairs the damage, actually making the muscle tougher and more sinewy.

5.   Initially, the body can repair the damage, but over time the nerves become scarred and stop transmitting signals.

6.   Nature may have designed ATP as a healing mechanism, to build new vessels so the body can repair tissue damaged by injury or disease, said Pizzo.

7.   Wiencke said such youthful smoking on a daily basis causes lung damage that the body cannot repair.