I was wondering if someone who smoked marijuana occasionally like once a week, sometimes twice a week which only lasted for 6 months then a break, is the lung darkened or ruined and can it recover back to healthy lungs if it is? age 21, new to smoke.

SOME BASICS: The lungs has some ability to remove debris from deep in the lung. It comes in handy to remove dust/dirt & other material casually inhaled during breathing. Any form of smoking exceeds this set of defenses. If you stop your lungs have a chance to clean up & become healthy. Some of the darkest/dirtiest lungs I ever saw were from a smoker at autopsy. Your choice.

Lung health: Please do give your lungs a chance to recover. Inhaling any foriegn substances into your lungs (to include marijuana) will cause damage. But yes, you do have th opportunity at age 22 for a do over and to make healthier choics.

Agree with Dr. F: MJ is not only damaging your lungs but your brain as well. Have a healthy diet, exercise 30 minutes/day, drink plenty of water, have safe sex, no tobacco alcohol weed or street drugs. For nutrition: http://www.choosemyplate.gov/. Get HPV vaccine. Wish you good health!