Cardiovascular Concerns

Urgent first

For severe or sudden symptoms after cannabis, NIDA says to seek immediate medical attention by calling 911 (US) or going to an emergency department. [1] This page does not tell anyone how to judge their own heart risk.

How to read this page

This is education, not medical advice. It does not tell anyone to start, stop or change a medicine. Evidence labels: evidence of harm (an association seen in studies), mixed, insufficient evidence. An association means two things occur together; it does not prove one caused the other. A "risk ratio" compares chances between groups; 1.0 means no difference.

Short-term effects

NIDA says cannabis can increase heart rate and blood pressure right after use. [1] Health Canada lists an increased heart rate among possible effects, "which can be dangerous for people with heart conditions." [2] Label: established for a short-term rise in heart rate.

Heart attack, stroke and heart rhythm

NIDA says some research shows an association between long-term cannabis use and an increased risk of stroke, heart attack and arrhythmias (irregular heartbeat), but more research is needed to learn whether the link is direct or due to other factors. [1]

A 2025 systematic review and meta-analysis in the journal Heart pooled 24 studies (17 cross-sectional, 6 cohort and 1 case-control) published from 2016 to early 2023. It estimated risk ratios of 1.29 for acute coronary syndrome (which includes heart attack), 1.20 for stroke and 2.10 for cardiovascular death among people who used cannabis. It found no statistically significant association for a combined outcome of acute coronary syndrome and stroke, measured in only two studies. [3] Cohort-only analysis gave similar results (risk ratio 1.32). [3] The studies were mostly observational and often based on self-reported use, and people who use cannabis may differ in other ways, such as tobacco use. Label: evidence of harm (association); size and cause uncertain.

What professional bodies say

The American Heart Association's 2020 scientific statement reviewed medical and recreational cannabis and concluded that cannabis may have therapeutic benefits but few are cardiovascular, while many of the concerning health implications of cannabis include cardiovascular diseases, although they may be mediated by the way it is delivered. [4] A 2022 American Heart Association statement on brain health said the increased risk of stroke reported in marijuana users raises concerns about long-term effects on cognitive function. [5]

Route matters

NIDA says smoke from cannabis products contains many of the same toxins, irritants and carcinogens as tobacco smoke. [1] The AHA statement notes that cardiovascular harm may depend on how cannabis is delivered. [4] See smoking and vaping cannabis: respiratory and other risks.

Special groups

• People with heart disease or high blood pressure. Health Canada warns the heart-rate rise can be dangerous with heart conditions. [2] Whether an individual with heart disease can use any cannabis product safely was not established in the sources read, so this page gives no guidance beyond talking with a cardiologist.
• Older adults and multiple medicines. NIDA notes cannabis use is rising among adults aged 50 and over. [1] See older adults and multiple medicines.
• People taking blood thinners. Separate from heart effects, case reports link cannabinoids with changes in warfarin effect; see CBD-medication interactions.

CBD and the heart

Proper evidence not found: the sources read for this page (NIDA, Health Canada, the Heart meta-analysis abstract and the AHA statement abstracts) did not report cardiovascular outcome data specific to CBD products, so no claim is made. The Heart meta-analysis studied cannabis use, and only one included study focused on medical cannabis. [3]