Current research links regular cannabis use, especially smoking it, to a higher risk of heart attack, stroke and cardiovascular death, and the American Heart Association advises against smoking or vaping cannabis. Most of the evidence is observational, so it shows association rather than proof of cause, and some long-running studies found no link at moderate use levels. No cannabis product is approved to prevent or treat heart disease.
This page used to summarize a single 2006 study. The field has moved a long way since then. Cannabis use has grown with legalization, researchers now have data on hundreds of thousands of people, and the American Heart Association (AHA) has issued a formal scientific statement. Below is what the major studies found, how strong the evidence is, and what it means if you use cannabis or have a heart condition.
What Cannabis Does to the Heart and Blood Vessels
The short-term effects are well documented. The CDC notes that cannabis can make the heart beat faster and raise blood pressure right after use. A Harvard study in Circulation described the same pattern: a dose-dependent rise in heart rate, higher blood pressure when lying down and a drop in blood pressure on standing. For a healthy young adult that is usually harmless. For someone with narrowed coronary arteries, a faster heart needs more oxygen, which is one proposed way cannabis could trigger a cardiac event.
Newer work looks at the blood vessel lining (the endothelium), which controls how arteries widen. In a small 2025 UCSF study in JAMA Cardiology, chronic cannabis smokers and regular THC-edible users both had weaker artery dilation than nonusers, at levels similar to those seen in tobacco smokers. The study had only 55 participants and could not prove cause, but it suggests that avoiding smoke may not remove all of the vascular effect.
Smoke itself matters too. The CDC points out that cannabis smoke contains many of the same harmful substances found in tobacco smoke, and that it is hard to separate the effects of THC from the effects of combustion.
What the Large Studies Show
The research comes in several types: studies that time cannabis use against heart attacks, long cohort studies that follow people for decades, large national surveys and pooled analyses. They do not all agree, which is why the details matter.
| Study | Who was studied | Main finding |
|---|---|---|
| Mittleman et al., Circulation 2001 | 3,882 heart attack patients | Heart attack risk was 4.8 times baseline in the hour after smoking cannabis, then fell quickly |
| CARDIA, Am J Public Health 2017 | 5,113 young adults followed about 27 years | No association between lifetime or recent use and cardiovascular disease, stroke or cardiovascular death in middle age |
| Jeffers et al., JAHA 2024 | 434,104 U.S. adults (national survey) | Daily use linked to 25% higher odds of heart attack and 42% higher odds of stroke, after adjusting for tobacco |
| Kamel et al., JACC: Advances 2025 | 4.6 million adults 50 and under, health records | Heart attack risk about six times higher in cannabis users, though absolute risk stayed low (0.56% vs 0.09%) |
| Storck et al., Heart 2025 (meta-analysis) | 24 studies pooled | 29% higher risk of acute coronary syndrome, 20% higher stroke risk, about twice the risk of cardiovascular death |
| Vallée, JAMA Network Open 2024 | 121,895 UK Biobank adults | Heavy lifetime use linked to higher cardiovascular death in women; no significant link in men |
The picture that emerges: occasional or past use, as measured in the CARDIA cohort, has not shown a clear long-term effect, while frequent and daily use is repeatedly tied to more heart attacks and strokes in the newer, larger datasets. The 2017 National Academies review rated the evidence that smoking cannabis can trigger a heart attack as “limited” and found no evidence either way on long-term heart attack risk. Several large studies have been published since then, and they lean toward harm.
The American Heart Association’s Position
In 2020 the AHA published a scientific statement in Circulation, “Medical Marijuana, Recreational Cannabis, and Cardiovascular Health”. Its main points:
- Cannabis may have some therapeutic uses, but few of them are cardiovascular.
- Many of the health concerns tied to cannabis are cardiovascular, and they may depend on how it is used.
- The AHA recommends that people not smoke or vape any substance, cannabis included, because of the potential harm to the heart, lungs and blood vessels.
- It called for clear labeling of THC and CBD content and for removing cannabis from Schedule I so it can be studied properly.
The AHA also published the 2024 Jeffers study above in its own journal, and the authors concluded that heavier use was associated with higher odds of adverse cardiovascular outcomes.
Why the Studies Disagree
- Tobacco. Many cannabis users also smoke cigarettes. In the CARDIA cohort, cannabis was tied to artery calcium only among people who had also smoked tobacco. The Jeffers study, by contrast, still found higher heart attack and stroke odds among people who had never smoked tobacco.
- Dose. Most CARDIA participants used cannabis lightly. Newer studies capture more daily users and more potent products.
- Self-report. Most studies rely on people describing their own use, and few record form, potency or timing.
- Study design. Survey and health-record studies can show associations but cannot rule out other differences between users and nonusers. The Storck meta-analysis authors noted the lack of standardized exposure measures.
Smoking, Vaping and Edibles
Most of the heart data comes from people who smoked cannabis, a point the CDC makes directly. Smoke adds combustion products, so not smoking is the clearest way to lower risk. That does not make other forms risk-free: the 2025 UCSF study found edible users had impaired artery function too, and THC raises heart rate however it is taken. Edibles also take longer to kick in, which makes accidental high doses more common. Our Cannabis 101 guides cover how different forms compare.
Evidence at a Glance
| Claim | Evidence level | Source |
|---|---|---|
| Cannabis raises heart rate and blood pressure right after use | Strong | CDC; Mittleman 2001 |
| Smoking cannabis can trigger a heart attack in the following hour | Limited to moderate | National Academies 2017; Mittleman 2001 |
| Frequent or daily use is linked to more heart attacks and strokes | Moderate (observational, consistent) | Jeffers 2024; Storck 2025; Kamel 2025 |
| Light or past use raises long-term heart disease risk | Mixed | CARDIA 2017 |
| Cannabis prevents or treats heart disease | No supporting evidence | AHA 2020 |
Risks and Side Effects
- Fast heart rate, palpitations and dizziness on standing, especially with high THC doses.
- Higher odds of heart attack and stroke with frequent use, based on observational data.
- Lung irritation and bronchitis symptoms from smoking, covered in our cannabis and asthma guide.
- Possible interactions with heart medications, including blood thinners. Ask your doctor or pharmacist before combining cannabis or CBD with prescription drugs.
- Extra concern for people who also smoke tobacco, the group in which some studies, including CARDIA, found the clearest link to artery damage.
Talk to Your Doctor
Tell your doctor if you use cannabis, how often and in what form. It is relevant to your cardiovascular risk in the same way smoking and drinking are. This matters most if you have coronary artery disease, a prior heart attack or stroke, an arrhythmia, high blood pressure or diabetes, or take blood thinners or other heart medicines. If you choose to use cannabis, the lower-risk choices are to avoid smoking, use less often and keep THC doses low. Chest pain, pressure or shortness of breath after using cannabis is an emergency: call 911.
For more, see our coverage of cannabis and heart attacks, cannabis and atherosclerosis and the full cannabis research section.
Cannabis and Cardiovascular Health FAQ
Is marijuana bad for your heart?
Frequent use appears to raise cardiovascular risk. Large studies link daily use to higher odds of heart attack and stroke, and the AHA advises against smoking or vaping cannabis. Light, occasional use has not shown a clear long-term effect in the main U.S. cohort study.
Does cannabis raise blood pressure?
It can raise blood pressure and heart rate right after use, according to the CDC. Long-term, the CARDIA study found no significant link between lifetime cannabis use and developing high blood pressure over 35 years.
Are edibles safer for the heart than smoking?
They avoid smoke, which removes one source of harm, but they are not proven safe. A 2025 UCSF study found impaired artery function in regular edible users as well as smokers.
What does the American Heart Association say about marijuana?
Its 2020 scientific statement says cannabis has few cardiovascular benefits, raises cardiovascular concerns, and should not be smoked or vaped. It also called for better labeling and fewer research barriers.
Can CBD help heart health?
There is no good human evidence that CBD prevents or treats heart disease. Any benefit seen so far comes from lab or animal research.
Can young, healthy people have a heart attack from cannabis?
It is rare, but studies of adults 50 and under find higher heart attack rates among cannabis users than nonusers, even though the absolute risk remains low.
For adults 21+ in legal states. General information, not medical advice. Talk to a doctor before using cannabis for a health condition.