Key Points
- Smoked cannabis, regardless of how it is smoked, can harm lung tissues and cause scarring and damage to small blood vessels.
- More research is needed to understand the specific effects cannabis smoking may have on lung cancer and other respiratory diseases.
Lung Health and Smoking Cannabis
In general, cannabis is smoked using:12
- joints (hand-rolled cigarettes),
- bongs (pipes or water pipes),
- bowls, or
- blunts (cigars or cigar wrappers that have been partly or completely refilled with cannabis).
Smoked cannabis, regardless of how it is smoked, can harm lung tissues and cause scarring and damage to small blood vessels.34
Smoke from cannabis has many of the same toxins, irritants, and carcinogens (cancer-causing chemicals) as tobacco smoke.5 Smoking cannabis can also lead to a greater risk of bronchitis, cough, and mucus production,678910 though these symptoms generally improve when people who smoke cannabis quit.311
More research is needed to understand the specific effects cannabis smoking may have on lung cancer and other respiratory diseases like emphysema (lung condition that causes shortness of breath) and chronic obstructive pulmonary disease (COPD).
- Schauer GL, Njai R, Grant-Lenzy AM. Modes of marijuana use – smoking, vaping, eating, and dabbing: Results from the 2016 BRFSS in 12 States. Drug Alcohol Depend. 2020;209:107900. doi: 10.1016/j.drugalcdep.2020.107900.
- Schauer GL, King BA, Bunnell RE, et al. Toking, vaping, and eating for health or fun: marijuana use patterns in adults, US, 2014. Am J Prev Med. 2016;50(1):1-8. doi: 10.1016/j.amepre.2015.05.027.
- Tashkin DP, Simmons MS, Tseng C-H. Impact of changes in regular use of marijuana and/or tobacco on chronic bronchitis. COPD. 2012;9(4):367-374. doi: 10.3109/15412555.2012.671868.
- Wang X, Derakhshandeh R, Liu J, et al. One minute of marijuana secondhand smoke exposure substantially impairs vascular endothelial function. J Am Heart Assoc. 2016;5(8):e003858. doi: 10.1161/JAHA.116.003858.
- Moir D, Rickert WS, Levasseur G, et al. A comparison of mainstream and sidestream marijuana and tobacco cigarette smoke produced under two machine smoking conditions. Chem Res Toxicol. 2008;21(2):494-502. doi: 10.1021/tx700275p.
- 6. National Academies of Sciences, Engineering, and Medicine. The health effects of cannabis and cannabinoids: the current state of evidence and recommendations for research. Washington, DC: The National Academies Press; 2017. https://nap.nationalacademies.org/catalog/24625/the-health-effects-of-cannabis-and-cannabinoids-the-current-state. Accessed February 8, 2024.
- Aldington S, Williams M, Nowitz M, et al. Effects of cannabis on pulmonary structure, function and symptoms. Thorax. 2007;62(12):1058-1063. doi: 10.1136/thx.2006.077081.
- Moore C, Coulter C, Uges D, et al. Cannabinoids in oral fluid following passive exposure to marijuana smoke. Forensic Sci Int. 2011;212(1-3):227-230. doi: 10.1016/j.forsciint.2011.06.019.
- Tan WC, Lo C, Jong A, et al. Marijuana and chronic obstructive lung disease: a population-based study. CMAJ. 2009;180(8):814-820. doi: 10.1503/cmaj.081040.
- Taylor DR, Poulton R, Moffitt TE, et al. The respiratory effects of cannabis dependence in young adults. Addiction. 2000;95(11):1669-1677. doi: 10.1046/j.1360-0443.2000.951116697.x.
- Hancox RJ, Shin HH, Gray AR, et al. Effects of quitting cannabis on respiratory symptoms. Eur Respir J. 2015;46(1):80-87. doi: 10.1183/09031936.00228914.