October 24, 2026, 3:34 p.m. ET
The legalization of recreational marijuana in the United States was associated with a faster increase in hospitalizations for three cardiovascular diseases, according to a new study examining more than 50 million hospital discharge records.
The study, published Oct. 22 in the journal BMJ Open, found that hospitalization rates for atrial fibrillation, heart failure and heart attacks increased more quickly in the western United States after the sale of recreational cannabis became legal than in areas without similar laws.
Researchers analyzed hospital records from 2012 to 2018 in 13 Western states: Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington and Wyoming. They compared trends in hospitalizations before and after recreational marijuana sales became legal in the region with trends in areas without similar laws.
The findings suggest a possible association between legalization of recreational cannabis and cardiovascular health, but researchers cautioned that the study cannot establish that legalization is causing these increases.
What heart diseases were potentially linked to legalization?
Researchers looked at hospital admissions for six cardiovascular diseases: atrial fibrillation or flutter, acute heart failure, heart attacks, ischemic stroke, venous thromboembolism (blood clots), and ventricular tachycardia (rapid heartbeat).
After accounting for other factors that might affect the results, the researchers found that hospital admissions increased faster each year in all 13 states after the sale of recreational marijuana became legal. Compared to regions without similar laws, hospitalization rates increased just over 2% faster for atrial fibrillation, almost 4% faster for heart failure, and just over 3% faster for heart attacks.
Rates of hospitalization for stroke, blood clots and ventricular tachycardia also tended to increase, but the differences were not statistically significant.
The analysis looked at more than 50 million hospital discharge records from the National Inpatient Sample, a database covering participating states that represent approximately 97% of the U.S. population.
Before recreational marijuana sales became legal, hospitalization rates for the conditions studied were lower in the 13 Western states than in areas without similar laws.
How Could Cannabis Affect Heart Health?
Cannabis may affect cardiovascular health through several physiological mechanisms, the researchers said. These include changes in heart rate and blood pressure, as well as potential effects on blood clotting.
Legalization has also been associated with more widespread cannabis use, particularly among older adults, who already face increased cardiovascular risks, the study found.
As of June 2025, recreational cannabis was legal in 24 states, while medical cannabis was legal in 41 states, the researchers noted.
The study has limitations
The study cannot prove that legalizing recreational marijuana led to an increase in hospitalizations. Researchers could not determine whether each patient used cannabis before developing heart problems, distinguish between methods of cannabis use, or explain changes in illegal cannabis use.
“Although an observational study cannot prove causality, our results highlight the potential harmful effects of recreational legalization on population health,” the researchers wrote.
They said additional research and continued monitoring of cardiovascular health is needed as more places legalize recreational cannabis.
Reporter Anthony Thompson can be reached at ajthompson@usatodayco.com or on X @athompsonUSAT
Gn Health
