what are the negatives of marijuana
Other physical effects of marijuana include: 1  Dizziness. 2  Shallow breathing. 3  Red eyes and dilated pupils.  Dry 1  mouth. Increased appetite.  Slowed reaction time (If you drive after using marijuana, your risk of being in a car accident more than doubles.)
Breathing In the Smoke. Marijuana smoke is also filled with many of the same chemicals as tobacco smoke, including ammonia, hydrogen cyanide, and formaldehyde. Some of these chemicals are known to cause cancer. Most users smoke pot in a joint or water pipe, so they breathe the smoke straight into their lungs. There's no proof that smoking marijuana causes lung cancer like cigarettes do. But people who smoke pot do show signs of damage and precancerous changes in their lungs, especially if they also smoke cigarettes.