Marijuana users are much more likely to suffer a heart attack, stroke or other life-threatening heart condition than people who don’t use, a new study says.
Adults under 50 are more than six times as likely to suffer a heart attack if they use marijuana, compared to non-users, researchers reported March 18, 2025, in the journal JACC Advances.
They also have a dramatically higher risk of stroke, heart failure and heart-related death, researchers said.
“Asking about cannabis use should be part of clinicians’ workup to understand patients’ overall cardiovascular risk, similar to asking about smoking cigarettes,” lead researcher Dr. Ibrahim Kamel, a clinical instructor at the Boston University Chobanian & Avedisian School of Medicine, said in a news release.
Kamel and his team utilized data from TriNetX, a global health research network, to conduct the retrospective study.
The participants, all aged 50 and under, had no major heart issues at the outset, with healthy blood pressure, cholesterol levels and no history of diabetes, tobacco use or coronary artery disease.
After an average follow-up of more than three years, they found that cannabis users had more than a sixfold increase in heart attack risk and double the chance of heart failure.
But the risks don’t stop there. Marijuana users were found to have a fourfold increased risk of ischemic stroke — a condition where a blood clot disrupts blood flow to the brain — and a threefold increased risk of cardiovascular death, heart attack or stroke.
Kamel’s team combed through data from 12 studies involving over 75 million people, including research from the US, Canada and India.
Seven of the studies found a strong link between cannabis use and heart attack risk, while four showed no significant difference and one showed a slightly negative association.
When they pooled all the data together, researchers found that active cannabis users were 1.5 times more likely to suffer a heart attack than those who didn’t use the drug.
However, Kamel pointed out some limitations in the study. Researchers didn’t consider the amount and duration of cannabis use, nor did they explore other potential contributing factors.
“We should have some caution in interpreting the findings in that cannabis consumption is usually associated with other substances such as cocaine or other illicit drugs that are not accounted for,” Kamel said.
He added, “Patients should be forthcoming with their doctors and remember that we are their number one advocate and having the full story matters.”
Proponents have long lauded the medicinal benefits of cannabis, including helping people break free from opioid addictions, easing chemotherapy side effects and treating insomnia. Additionally, many rely on marijuana to manage chronic pain and alleviate symptoms of depression and post-traumatic stress disorder.
However, there are growing concerns over the potential harms of regular and long-term use.
Multiple studies have linked cannabis to an elevated risk of heart attacks, cardiovascular disease and stroke. Still, the precise ways marijuana impacts the cardiovascular system remain unclear.
Kamel and his colleagues hypothesize that cannabis may interfere with heart rhythm regulation and increase the oxygen demand in the heart muscle. They also suggest the drug could contribute to endothelial dysfunction, making it harder for blood vessels to relax and expand, which disrupts blood flow.
Other research has linked cannabis use to impaired brain function, mental health issues, gastrointestinal problems and an increased risk of developing head, neck or throat cancer. Smoking marijuana can also cause damage to your lungs.
There’s also the risk of becoming addicted to marijuana. About 3 in 10 users develop a cannabis use disorder, characterized by compulsive use despite negative consequences, according to the Centers for Disease Control and Prevention.
