Marijuana can also cause chronic lung disease. A harmful habit Marijuana impairs brain functions, hampers memory and judgment, distorts perception, and diminishes motor functions. It increases the heart rate by as much as 50 percent, increases blood pressure, and reduces the supply of oxygen to the body. The drug also decreases testosterone levels in men, interferes with women's menstrual cycle, and weakens the body's immune system. Have a drink with a joint, and you're primed for an accident.
Marijuana can cause dependence, and smokers quickly build up a tolerance for the drug.