marijuana effects high blood pressure

How does cannabis affect blood pressure?

Copy article link to clipboard.

Link copied to clipboard.


  1. Does marijuana lower or raise blood pressure?
  2. What are the cardiovascular effects of cannabis?
  3. Weed and blood pressure medication
  4. Other effects of weed on blood pressure

Since smoking a joint can lead to a relaxing high, you might wonder about cannabis use and its effect on blood pressure. We know that weed can make your eyes red , but does it also raise or lower blood pressure, or does it not have any effect at all? If you have high blood pressure, is marijuana safe to consume?

Here we’ll address how smoking weed, including medical marijuana, could factor into your blood pressure levels.

Does marijuana lower or raise blood pressure?

To answer this question, we should focus on two of the primary cannabinoids present in cannabis : cannabidiol (CBD) and tetrahydrocannabinol (THC). Both may exert an influence on blood pressure levels.

Dr. Bonni Goldstein, a medical adviser to Weedmaps and the director of Canna-Centers in Lawndale, California, outlined the potential effects of THC on blood pressure:

“THC can affect blood pressure depending on the dose, the route of administration, a person’s experience with THC, and a person’s underlying health. Healthy volunteers that took THC had an increase in heart rate and decrease in blood pressure. In studies where people used THC while lying down, they had elevated blood pressure. When they stood up, their blood pressure dropped and they experienced low blood pressure.”

These sudden drops in blood pressure, also known as white outs or green outs, may indeed be linked to cannabis use. Dr. Melanie Bone, a board-certified OB-GYN and cannabis specialist who practices in West Palm Beach, Florida, told Weedmaps that “cannabis may cause a drop in blood pressure on standing — known as postural hypotension.” This type of drop in blood pressure is not desirable, as it can cause vertigo and even fainting. So, when we talk about “lowering blood pressure,” we do not necessarily consider that effect beneficial to health.

Both THC and CBD may lower blood pressure in different ways. However, neither CBD nor THC should be considered a medical treatment for high blood pressure. Photo by: Gina Coleman/Weedmaps

Image lightbox

And how does CBD affect blood pressure? The consensus is that CBD tends to relax the blood vessels and decrease anxiety, which ultimately leads to a lowering of blood pressure. This type of blood pressure reduction is more favorable, as it is associated with decreased levels of anxiety. Both THC and CBD may lower blood pressure in different ways. However, based on available research, neither CBD nor THC should be considered a medical treatment for high blood pressure.

What are the cardiovascular effects of cannabis?

Another frequently asked question about cannabis and cardiovascular health is: can weed cause a heart attack?

First, let’s again distinguish between the cannabinoids THC and CBD. For example, CBD oils containing trace levels of THC may have very different effects than smoking a high-THC strain of marijuana. Various studies have indicated that THC may have detrimental effects on cardiovascular health, whereas CBD could be helpful to the heart.

Goldstein added, “CBD does not appear to have the same risks for the heart as THC and in fact, appears to be somewhat cardioprotective.” To support this assertion, Goldstein cited a 2010 study published in the Journal of the American College of Cardiology in which researchers concluded that CBD has therapeutic potential in treating complications of diabetes, as well as some cardiovascular disorders. Most notably, CBD could reduce inflammation, a condition that can ultimately damage the blood vessels, arteries, and vital organs. So, if you apply CBD oil to your skin or swallow a few tablespoons, the impact could differ greatly than if you smoked a blunt.

To this point, there is some research that suggests smoking THC could directly or indirectly lead to a heart attack. One 2019 study titled “The Cardiovascular Effects of Marijuana: Are the Potential Adverse Effects Worth the High?” and published in the Journal of the Missouri State Medical Association showed that some people experienced a heart attack within an hour of smoking cannabis.

Bone, however, argued, “On careful study, many of the patients also smoked cigarettes and were obese, making it hard to draw absolute conclusions. Also, the observations were made on cannabis of unknown origin, not cannabis from a dispensary.” The fact that the cannabis did not come from a registered dispensary is significant, as there is no available lab testing to determine what other compounds may have been present.

The bottom line is that there have been studies demonstrating a questionable association between smoking weed and having a heart attack, and more research is necessary.

Weed and blood pressure medication

You might also be wondering, what if you’re smoking weed while taking blood pressure medication? Will there be an adverse reaction? If you are smoking THC-rich cannabis and taking medication for high blood pressure, the answer is that there could be.

Goldstein explained, “Smoking cannabis can be harmful for those with heart disease or hypertension since the smoke contains carbon monoxide. This gas binds to the hemoglobin in red blood cells, displacing oxygen off of the red blood cells which results in less oxygen going to the body’s tissues, including the heart. People with heart disease or high blood pressure should avoid smoking.”

Instead, Goldstein recommends other methods of cannabis use, such as sublingual tinctures or edibles, which she says are safe to use if someone is on blood pressure medication. Further, Bone stressed that people who use cannabis and are on blood pressure medications need to be mindful of the possibility of an interaction with other prescription medications. This means monitoring blood pressure and reporting any dizziness to your doctor, who can adjust your dosages accordingly.

People who use cannabis and are on blood pressure medications need to be mindful of the possibility of an interaction with other prescription medications. Photo by: Gina Coleman/Weedmaps

Image lightbox

In particular, the blood thinner warfarin was shown in a 2017 study published in the journal Epilepsy & Behavior Case Reports to interact with cannabidiol (CBD) in certain epileptic individuals . In line with Bone’s advice, researchers concluded that patient lab work should be monitored closely.

While it is possible for warfarin and other medications to interact with cannabis, there are no guarantees, and the 2017 study focused on patients with epilepsy rather than on the general population. As Dr. Bone reported, “In my private practice, I have not encountered a significant negative interaction between blood pressure medication and cannabis.”

Other effects of weed on blood pressure

There may be other effects of marijuana on blood pressure that health practitioners have yet to discover. All potential effects depend on the individual’s existing health problems, especially co-morbid conditions such as diabetes and obesity.

Can people without these conditions safely indulge in marijuana? A healthy individual’s body may appear as a well-oiled machine, but Bone disputes that analogy, pointing out that, “Unlike a car, where we replace the brakes or tires, the heart never gets a vacation and the blood vessels need to keep working forever. And the nervous system, which directs the show like a conductor, is on duty 24/7.”

Moderation, then, may be key in integrating a cannabis regimen into your healthcare plan. Consult with your physician before you begin using cannabis or CBD products and discuss any medications you are currently taking.

Learn how cannabis affects blood pressure and what questions you should ask your doctor before starting a regimen.

How Cannabis May Affect Your Heart Health

Share on Pinterest Researchers are learning how THC in cannabis may affect the heart.

  • THC is the main mind-altering (psychoactive) ingredient in cannabis, or marijuana, that can cause a person to feel high.
  • THC-containing products stimulate the heart as well as promote vascular inflammation and oxidative stress.
  • This may lead to elevated blood pressure, abnormal heart rhythms, and overall higher risk of heart attack, stroke, and sudden death.

Cannabis may have medicinal properties, but it could also be harmful to the heart and blood vessels, according to a report from the American Heart Association (AHA).

The AHA’s statement in the journal Circulation looked at several studies on the topic, as cannabis use has increased over the past decade.

Cannabis, also known as marijuana, refers to the varieties of cannabis plants that contain tetrahydrocannabinol (THC).

THC is the main mind-altering (psychoactive) ingredient in cannabis that can cause a person to feel high. Cannabinoids are compounds in cannabis. Cannabidoil or CBD is a commonly known cannabinoid said to have some health benefits. CBD is different from THC.

Researchers have had a tough time trying to study cannabis, as it is listed by the U.S. Controlled Substances Act as a Schedule 1 controlled substance. By definition that means it does not have a medical use and is likely to be misused. In the report, the AHA encouraged the federal Drug Enforcement Administration to remove it from the designation.

Chemicals in cannabis have been linked to higher risk for heart attack, heart failure, and atrial fibrillation. But those studies are observational and did not prove that the chemicals were the cause for the increased risk.

One study cited in the AHA statement reported that 6 percent of patients under the age of 50 who had a heart attack used cannabis. It was linked to having worse all-cause and cardiovascular mortality. Another study noted a significantly higher chance of having a stroke in cannabis users ages 18 to 44, with even greater odds in those who consumed it more frequently compared to those who did not use cannabis.

Dr. Chip Lavie, a cardiologist at the Ochsner Medical Center in New Orleans, Louisiana, said it’s already known that cannabis can have adverse effects on coagulation, increase acute cardiovascular events, and lead to poor vascular effects.

“We still do not have a feel on the impact on occasional users, high dose users, and very chronic users,” Lavie told Healthline.

When cannabis is used on a short-term basis in some patients, the benefits may outweigh the risks. Additional dangers with impure products and vaping still exist, though, he noted.

Dr. Muthiah Vaduganathan, a cardiologist at Brigham and Women’s Hospital in Boston, Massachusetts, pointed out that certain forms of cannabis delivery, such as vaping, can have unique cardiovascular health implications.

Because cannabinoid receptors are distributed all over the body, including in the heart, there’s a potential impact for effects on the heart, Vaduganathan said.

Not all the research on cannabis shows harm, the AHA report stated.

THC-containing products stimulate the heart as well as promote vascular inflammation and oxidative stress. This may lead to elevated blood pressure, abnormal heart rhythms, and overall higher risk of heart attack, stroke, and sudden death, explained Dr. Michael Miller, a cardiology professor at University of Maryland School of Medicine.

If THC concentrations are too high, or taken in a short amount of time, there’s the potential for it to create adverse reactions such as in older people on existing medications.

In contrast, CBD-containing products reduce inflammation and emotional stress that in turn, may serve to reduce the risk heart disease.

“I was not aware of the potential opposing effects between THC in the promotion of heart disease as compared to CBD which may protect against its development and progression,” Miller noted.

Although cannabis can be an effective treatment for medical purposes such as seizure control, or reducing nausea and improving appetite in people with cancer or HIV, some people aren’t aware of its potential harms when used for recreational or nonproven purposes, Miller said.

Miller hopes to see a well-designed clinical trial to determine whether daily use of CBD reduces the risk of a heart attack, stroke, or cardiovascular death.

Experts cite a lack of robust data in specifying the harms and benefits of cannabis on the cardiovascular system. Due to rising concentrations of THC in cannabis, earlier studies may only reflect the impacts of lower levels of THC on people, the AHA report stated.

Most cannabis studies are observational and don’t take into account that some cannabis users also smoke cigarettes, Miller added.

“I would love to know whether, and to what extent, THC may be harmful to the heart in the absence of major risk factors such as cigarette smoking,” he added.

Dr. Stephen Sidney, a senior research scientist with the Kaiser Permanente Northern California Division of Research in Oakland, California, said more research is urgent, as more people 65 and older are using cannabis — and they are at the highest risk for heart attack.

“Most of what we know about the cardiovascular effects of marijuana comes from studies of smoked marijuana. Much more research needs to done on other forms of marijuana, such as edibles, tinctures, and topic preparations,” Sidney told Healthline. “We also need to study how marijuana vaping affects the heart and lungs, because this has overtaken smoking of marijuana cigarettes as the most common use by teens.”

Patients and doctors need to be open about cannabis use and implications, Vaduganathan said.

“While cardiologists often ask and counsel patients about tobacco use, they infrequently screen for cannabis use. Patients similarly may not recognize that cannabis can have important effects on blood pressure, cardiovascular drug metabolism, and overall heart health — some of these may actually be very similar to the adverse health effects of tobacco smoking,” Vaduganathan said.

Marijuana may have medicinal properties, but it could also be harmful to the heart and blood vessels, according to a report from the American Heart Association (AHA).