Respiratory and Lung Health

Heavy marijuana smoking is associated with tissue damage in the lungs’ airways.1 People who smoke marijuana daily or near-daily more often experience a daily cough, mucus and wheezing. More research is needed to see whether this damage increases the likelihood of developing other lung diseases.


Current evidence shows a link between marijuana use and testicular cancer.2 There is not enough data available on marijuana’s relationship with other types of cancer. 

Heart Health

One study has shown that marijuana increases the risk of having a heart attack within the first hour of smoking to five times that of non-smokers.3  Within the second hour, the heart attack risk declines to 1.7 times that of a non-smoker, and returns to an average risk after two hours. More research is needed to understand the impact of marijuana use on the heart.

Mental Health

Early research has shown that daily or near-daily use of marijuana can damage a user’s memory, and negatively impacts thinking and problem solving abilities.4,5 Marijuana, especially in high amounts, can also cause temporary psychosis (not knowing what is real, hallucinations and paranoia).6 Finally, marijuana is an addictive substance, similar to other legal products like tobacco, alcohol, and prescription drugs.


1. Tashkin, D.P. (2013). Effects of Marijuana Smoking on the Lung. Annals of the American Thoracic Society. 10(3). Retrieved June 2018 from:

2. Lacson J.C., Carroll J.D., Tuazon E, Castelao E.J., Bernstein L., Cortessis V.K. (2012). Population-based case-control study of recreational drug use and testis cancer risk confirms an association between marijuana use and nonseminoma risk. Cancer. 118(21), 5374-5383. Retrieved June 2018 from:

3. Mittleman, M.A., Lewis, R.A., Mackure, M., Sherwood, J.B., Muller, J.E. (2001).Triggering Myocardial Infarction by Marijuana. Circulation. 103(23), 2805-2809. Retrieved June 2018 from:

4. Brenner, G.H. (2018). Neuroimaging, Cannabis, and Brain Performance & Function: A fastidious meta-review and synthesis of the existing research brings clarity. Psychology Today. Retrieved on June 2018 from:

5. Crean, R. D., Crane, N. A., & Mason, B. J. (2011). An Evidence Based Review of Acute and Long-Term Effects of Cannabis Use on Executive Cognitive Functions. Journal of Addiction Medicine, 5(1), 1–8. Retrieved June 2018 from:

6. Shrivastava, A., Johnston, M., & Tsuang, M. (2011). Cannabis use and cognitive dysfunction. Indian Journal of Psychiatry, 53(3), 187–191. Retrieved June 2018 from:

7. National Institute on Drug Abuse. Marijuana: Is Marijuana Addictive? Marijuana Research Report Series. Retrieved June 2018 from:


Last modified on 08/15/2023