How does cannabis affect blood pressure?
Copy article link to clipboard.
Link copied to clipboard.
- Does marijuana lower or raise blood pressure?
- What are the cardiovascular effects of cannabis?
- Weed and blood pressure medication
- 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
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
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 Affects Your Blood Pressure
Research suggests that marijuana can impact blood pressure in humans. Some studies even indicate that cannabis use could be a helpful way to lower blood pressure and treat conditions like hypertension. Still, other research shows conflicting results — that it could be a risk factor for increased blood pressure. While we don’t yet have enough evidence, scientists continue to study whether and how it could be effective.
How cannabis impacts blood pressure
Cannabis works primarily by modulating a system in the human body known as the endocannabinoid system. This system includes chemicals naturally produced by the human body called endocannabinoids, cannabinoid receptors, which are activated by endocannabinoids, and enzymes which clear the endocannabinoids from the body. This system is believed to be responsible for maintaining homeostasis or balance in a wide range of bodily functions, including mood, sleep, energy, hunger, and pain response.
The chemicals in cannabis, called cannabinoids, are also able to trigger these cannabinoid receptors, and thus modulate many of the functions that the endocannabinoid system is involved in regulating.
Studies have revealed that the endocannabinoid system plays a key role in cardiovascular activity. In animal studies looking at these cardiac factors, researchers have noted that activation of this system can cause significant changes in heart rate, blood vessel constriction, inflammation, oxidation, and blood pressure — both increasing and decreasing blood pressure in different contexts.
In cardiovascular disease states we generally see an upregulation of the endocannabinoid system, so researchers believe that the body’s endocannabinoids play a role in the progression of cardiovascular disease.
In particular, there are studies that show an association between an overactive endocannabinoid system and maladies like arterial, pulmonary and portal hypertension.
Still, researchers aren’t sure whether these elevated endocannabinoid levels are causing these problems with heart health, or if they are being deployed by the body as a counteractive measure to balance out the problems.
When tested in animal studies, endocannabinoids have shown both the potential to widen blood vessels, thereby lowering blood pressure, and to contract blood vessels, thus raising blood pressure.
The evidence cannabis lowers blood pressure
Given what we know about how the endocannabinoid system and how it impacts blood pressure, it’s likely that the cannabinoids present in cannabis will also have some effects. Because of this, there is great interest in the therapeutic potential of cannabis for modulating blood pressure.
Anecdotally, many medical cannabis users report that cannabis has increased their cardiovascular health and well-being. Unfortunately, the actual research on this is somewhat limited and conflicted.
Some studies suggest that cannabis use can lower blood pressure and reduce risk of hypertension. For example, animal studies on rodents with high blood pressure found that activating the endocannabinoid system by adding cannabinoids reduced blood pressure, while blocking cannabinoid receptors increased blood pressure.
In one review of the literature, researchers reported that cannabis doesn’t have an immediate impact, but can lead to longer term lowering of blood pressure. In these studies, while they found increased heart rate with use, they didn’t see immediate changes in blood pressure. Still, this review found that chronic cannabis use was tied to lower blood pressure and heart rate overall.
In another study, researchers found that cannabis withdrawal could lead to spikes in blood pressure. Researchers observed and monitored heavy cannabis users before and after a period of cannabis abstinence. While the cannabis users had normal blood pressure before going cold turkey, abruptly stopping caused some participants’ blood pressure to spike — actually hitting hypertensive ranges.
Since this only impacted 31% of the participants, researchers on this study hypothesised that cannabis might be offering protection from high blood pressure and, when that protection was removed, these patients stopped benefiting from cannabis’ blood pressure lowering effects. For those with heart problems who are already using cannabis, the authors of this study suggest that stopping should only be done under doctor supervision to ensure that blood pressure levels stay in a safe range.
While we might assume that these studies reflect impacts from THC, the primary cannabinoid in cannabis, it’s also important to note that cannabis contains many different compounds. It’s possible some of the research is conflicted because different types of cannabis may have different effects.
For example, research looking at the cannabinoid CBD, while limited, suggests that it can both lower blood pressure directly and reduce stress that can cause increases in blood pressure. Some researchers even suggest CBD may be helpful for treating hypertension. Another study found that blocking endocannabinoid receptor activity reduced blood pressure for obese patients with hypertension. Still this research is in early phases and more needs to be investigated before we can make any firm conclusions.
The evidence cannabis raises blood pressure
The studies above indicate that cannabis may be a helpful treatment for those suffering from high blood pressure. Still, other research suggests the opposite, with findings suggesting that cannabis can actually increase blood pressure. For example, one study on six individuals found that recent cannabis use temporarily increased blood pressure within an hour of taking the medicine.
A review of the literature on cannabis and heart health didn’t find any links between cannabis use and hypertension, but it did find some evidence that suggested cannabis use leads to an increased risk of ischemic stroke — another condition associated with high blood pressure.
Survey based studies have added to this confusing state of affairs. One study looked at the correlation between blood pressure and cannabis and reported that those who had ever used cannabis (even just once) were more than three times more likely to die from high blood pressure. Still, this survey was limited because it did not look at dosing, frequency of use, or chemical profile, and it is unclear whether those surveyed may have used other illicit drugs, and if so, whether those were a factor.
In a later survey study, researchers found no relationship between ongoing cannabis use and high blood pressure. They did find that recent cannabis use led to increased systolic blood pressure, but chronic cannabis use did not seem to impact blood pressure in any way. Even for those who regularly used cannabis throughout their life, there was no association with increased blood pressure.
These studies on cannabis and blood pressure certainly present a confusing picture. And researchers continue to investigate to try to find a way to clarify the role these cannabinoids play.
Risk factors for cannabis and blood pressure
Cannabis and its effects on the cardiovascular system remain unclear. Findings support both an increasing as well as a lowering effect on blood pressure. Randomized prospective trials are needed to answer many questions surrounding the therapeutic use of cannabis.
Those who are already using cannabis should also exercise caution in stopping the medication, as a sudden withdrawal from cannabis use could trigger increased blood pressure in some.
Because of these serious risk factors, anyone considering cannabis — particularly anyone who already has issues with pre-existing cardiovascular conditions — should be cautious and always check with their doctor before starting any cannabis regimen.The evidence is inconclusive, with some studies showing raised BP and others lowered BP. Short-term vs long-term effects could also differ. ]]>