Other Marijuana Effects on the Body

Because marijuana contains irritants and carcinogens, it promotes cancer of the lungs and other parts of the respiratory tract. Marijuana also produces high levels of an enzyme that converts some hydrocarbons into their carcinogenic form. These levels may accelerate the changes that ultimately produce malignant cells. Additionally, marijuana users typically inhale more deeply and hold their breath longer than tobacco smokers, increasing the lungs exposure to carcinogenic smoke.

Users who smoke marijuana regularly may experience the same respiratory problems as tobacco smokers, including daily cough and phlegm, symptoms of chronic bronchitis, and frequent chest colds. Continued marijuana use can result in abnormal functioning of lung tissue injured or destroyed by marijuana smoke.

Within a few minutes after smoking marijuana, the user's heart begins to beat more rapidly and may increase by 20 to 50 beats per minute or double. Results of a study released in 2001 indicate that a person's risk of heart attack within the 1st hour of smoking marijuana is four times the usual risk.