Marijuana and blood pressure
Feb 16, 2020
Does marijuana help high blood pressure?
Cannabis has been suggested as a potential treatment for hypertension, but there are concerns that it might actually exacerbate the condition.
The endocannabinoid system is involved in the regulation of blood pressure, so it is possible that manipulating this system could prove therapeutically helpful for the treatment of hypertension — or it is possible that it may worsen it. Unfortunately there is very little research on using cannabis for this purpose, and what research we do have is both limited and conflicted.
While scientists don’t have enough data to recommend cannabis for this condition, they do recommend continued research into whether cannabis, and CBD in particular, might be able to help.
How Cannabis Works on Hypertension
The endocannabinoid system (ECS) exists in all vertebrates and helps regulate crucial functions such as sleep, pain, and appetite. The human body produces its own cannabinoids, which modulate and activate its various functions. But as its name suggests, the endocannabinoid system can also be modulated and activated by cannabinoids found in the cannabis plant. Because the entire system was only discovered in the past 30 years, scientists still have much to learn about the myriad ways cannabis affects the human body.
As it turns out, this system is also involved in regulating the cardiovascular system. Researchers have found that the endocannabinoid system plays a key role in the adjustment of cardiovascular activity — and, in particular, strongly affects hypertension.
Activation of this system’s various receptors with endocannabinoids (such as anandamide) in animal studies has led to noticeable and clinically significant changes in cardiovascular effects such as the increase or decrease of blood pressure, heart rate, blood vessel constriction, inflammation, and oxidation. So it is clear that the endocannabinoid system impacts our cardiovascular functioning.
In addition, studies have found that the endocannabinoid system is overactive in arterial, pulmonary and portal hypertension. Still, it is relatively unclear from the research whether this elevation in endocannabinoid activity is playing a protective role, or a harmful one. This is in part because endocannabinoids can cause blood vessels to both widen and contract in different contexts — both increasing and decreasing blood pressure. These actions might be beneficial or harmful for different types of hypertension, so the implications of these effects can go both ways.
While researchers have a long way to go when it comes to understanding these impacts, some suggest that targeting this system with cannabinoid-based treatments could be an effective way to treat hypertension. Still researchers caution that more research needs to be done to better understand the long term implications of cannabinoids on the cardiovascular system, as well as their potential interactions with food and other medications that lower blood pressure.
Medical Studies on Cannabis and Hypertension
While we have clear evidence that cannabinoids impact our cardiovascular activity via the endocannabinoid system, we need to look to the research on humans to get a real picture of how it impacts hypertension. After all, animal studies give us a hint of how things might work for humans, but can sometimes point us in the wrong direction.
When it comes to the medical studies on marijuana and high blood pressure, our data is fairly limited — and what we do have is sometimes conflicted. Some studies report that acute cannabis use causes an increase in heart rate but no significant changes in blood pressure, and that chronic cannabis use can lead to long lasting decreases in blood pressure and heart rate. This could indicate a long term helpful role in reducing hypertension. Still, other studies suggest that the increased heart rate from cannabis consumption comes along with temporary increases in blood pressure.
To add to this confused picture, survey-based studies looking at smoking marijuana and blood pressure have also brought back conflicting results. An alarming study from 2005 found that those who had ever used cannabis (even just once) were more than three times more likely to die from hypertension than those who had never used the drug. Still, it’s important to note limitations of this survey. For one thing, many people underreport use of other illicit drugs, which might account for these issues. This survey also didn’t look at the frequency or dose of cannabis used, so it was limited by those factors.
Despite this frightening study, another survey-based study from 2016 found no relationship between cannabis use and hypertension. While they did find recent cannabis use was tied to an increase in systolic (but not diastolic) blood pressure, they found no associations between chronic cannabis use and blood pressure at all. Cannabis use was not associated with hypertension or prehypertension even when it was used regularly throughout someone’s life.
In addition, a review of previous literature on cannabis and cardiac health found limited evidence that cannabis use was tied to an increased risk of ischemic strokes, but did not report any link to hypertension.
But in another study on hypertension and cannabis, researchers found cannabis withdrawal could be a potential risk factor. In this study, researchers monitored blood pressure from heavy cannabis users before and after a period of abrupt abstinence from cannabis. These chronic cannabis users all had normal blood pressure while using cannabis but after suddenly stopping the drug, some participants saw their blood pressure skyrocket into hypertensive ranges. Researchers on this study pointed out that these changes could be directly related to the withdrawal process, or might be a secondary symptom related to factors such as the anxiety that accompanies withdrawal.
Interestingly, this study was on mostly older and African-American patients — two groups at risk for hypertension. This led researchers to wonder whether cannabis might be offering a protective effect from hypertension, which is removed when cannabis is no longer taken; or whether the spike in blood pressure is simply a withdrawal effect from stopping cannabis. More research which looks at blood pressure before beginning cannabis use (as well as during and after) is needed to disambiguate the cause of this hypertension.
Most of the participants (69%) did not see raises in blood pressure significant enough to be considered hypertension, so this is likely to affect a minority of cannabis users. Still, those with preexisting cardiac issues could face problems during withdrawal. The authors suggest that those with cardiac risk factors, who are considering stopping cannabis, should do so under physician observation to ensure blood pressure levels stay in a safe range.
Can CBD help with high blood pressure
While studies on cannabis in general present conflicting results about its relationship to blood pressure, this could be in part because cannabis has many potential active ingredients. While THC is known to cause cardiac effects like temporarily increasing heart rate, and in some cases blood pressure, CBD, another cannabinoid in cannabis, can actually reduce this effect from THC when they are taken together. On its own, CBD is known to reduce blood pressure, making it an attractive possibility for managing hypertension. Some studies point to it as a potential hypertension treatment to investigate, but much research needs to be done to confirm its efficacy.
Scientists have yet to conclude that cannabis is a safe option for those with hypertension, and we have very little data on what side effects are common for those with that condition. But given what we know about cannabis’ potential to impact cardiovascular activity, it is possible it could cause increased or decreased blood pressure and could increase your risk of other cardiac events like ischemic strokes.
If you are already using cannabis and have hypertension (or have had it before), or have other cardiac risk factors, you could also be at risk for increased blood pressure during withdrawal.
The Cannigma content is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Always consult with an experienced medical professional with a background in cannabis before beginning treatment.
Hypertension (HTN or HT), also known as high or raised blood pressure, is a condition in which the blood vessels have consistent alleviated pressure. The blood vessels deliver blood to all parts of the human body every time the heart beats. Therefore, when the blood pushes against the walls of the blood vessels, the heart finds it harder to pump. The higher the pressure, the harder it is for the heart to push back.
Though it barely shows any symptoms, high blood pressure in the long-term is considered a major risk factor for stroke, heart failure, vision loss, chronic kidney disease, atrial fibrillation, peripheral vascular disease, and dementia. Regardless of these conditions, continuous pressure for years can cause damage to blood vessels.
High blood pressure is classified as either primary (essential) or secondary. About 90–95% of cases are primary since they are caused by genetic factors and nonspecific lifestyle factors, such as smoking or drinking habits. Other cases are classified as secondary due to an identifiable cause such as another disease, like chronic kidney disease.
More than 25 of adults in the UK and 33% of adult Americans have high blood pressure. Unfortunately, only about half (54%) of those patients have the condition under control.
Hypertension is often called “the silent killer” since it hardly shows any symptoms. Patients sometimes report:
- Sleeping problems
- Chest pain
- Shortness of breath
In the case of hypertensive crisis (a very high level of hypertension), they also report headaches and nosebleeds or blood in the urine. It is a must, in this case, to see a doctor immediately.
However, in most cases, patients experience no symptoms at all, other than other conditions associated with hypertension like hypertensive retinopathies, a hypertension complication which affects the eye and can lead to blindness. If undetected for an extended period, the condition can cause damage to blood vessels, the cardiovascular system, the kidneys, and internal organs.
In fact, the only way of detecting hypertension at an early stage with certainty is to check your blood pressure regularly. Most doctors will take a blood pressure reading at every appointment or at least occasionally. If your personal medical history puts you at risk, you should discuss hypertension with your doctor.
The exact cause of hypertension is often unknown. However, in one out of 20 cases it has something to do with the effect of an underlying condition or medication. Chronic kidney disease (CKD), for example, is considered a common cause of the condition since it prevents the kidneys from filtering out fluid. Hypertension occurs when these fluid excesses the kidneys.
Several risk factors also increase the chances of having hypertension:
- Gender – hypertension is equally common in men and women, but men are more prone to it at a younger age while women are prone to it when they are older.
- Age – blood pressure can increase steadily with age, and hypertension is most common in people over the age of 60. However, sometimes children are also at risk because of unrelated reasons like family history and obesity.
- Heredity – high blood pressure tends to run in families.
- Alcohol and tobacco use – consuming large amounts of drugs and alcohol increases the blood pressure.
- Ethnicity – hypertension is more common in some ethnic groups. African Americans, for instance, develop the condition more often than white people.
- Obesity – significant excess weight is a key risk factor. Being obese requires large amounts of blood to deliver oxygen to different of the body, hence the heavier pressure on the artery walls.
- Other health conditions: this is called secondary hypertension since it is caused by conditions like diabetes, cardiovascular disease, chronic kidney disease, and high cholesterol levels.
Other contributing factors include:
- Physical inactivity – people who don’t exercise tend to have a higher heart rate, which forces the heart to beat faster and apply heavier pressure on the arteries with every beat.
- An unhealthy diet – a salt-rich diet or one combined of processed and fatty foods isn’t ideal for anyone, but it’s especially dangerous for anyone with the risk of hypertension. For a healthier diet, switch to foods which are high in potassium. Potassium lessens the effects of sodium, a compound found in salt, which reduces the kidney’s ability to get rid of water and thus contributes to hypertension as a result of their excessing with fluid. Potassium itself also helps in easing the tension in your blood vessel walls
- Certain medications – birth control pills, decongestants, and some pain relievers are known for raising blood pressure.
- Poorly managed stress – high-stress levels can temporarily increase blood pressure. If managed poorly by smoking tobacco or eating processed foods, stress might further increase the chances of hypertension.
- Long-term sleep deprivation – high blood pressure may cause sleep problems, but it might be a contributing factor if the patient is not sleeping due to stress or other related problems.
- Illegal drugs – mainly cocaine and amphetamines.
Since there are mostly no symptoms for hypertension, healthy adults over the age of 40 should have their blood pressure checked at least once every five years. An adult who might be at risk of developing the condition should be checked at least once a year.
Most clinics offer to perform a blood pressure test on every routine visit, but you can also ask for one. The test can also be conducted at some pharmacies and even health events in some workplaces, or you can test yourself at home using a home testing kit.
In its simplest form, the test requires a stethoscope, an arm cuff, a pump, and a dial. However, automatic devices are also common. During the test, the cuff will be pumped up to restrict the blood flow to the arm, in a squeeze that might feel slightly uncomfortable. After a few seconds, the pressure will be released slowly, and the detectors will sense vibrations in the arteries. The doctor may then step in to take the reading manually if needed.
The result is usually given straight away, either by the doctor or the machine performing the test. However, discovering high blood pressure on one test doesn’t always mean there is a reason for concern since sometimes patients are having a stressful time when visiting the doctor, which may affect the results.
In the case of a high reading, you may be asked to perform an additional test at home using a blood pressure monitor or to wear one that monitors your blood pressure throughout the day. The doctor may also recommend some extra routine tests, like a urine sample, a cholesterol test, and an electrocardiogram, to check for signs of heart disease.
The doctor will recommend treatment depending on the current blood pressure reading while considering the risk of developing other problems:
- If the current reading is consistently above 140/90mmHg but the risk is low – the treatment will likely include some suggested lifestyle changes
- If the current reading is consistently above 140/90mmHg but the risk is high – the treatment will likely also include medications that lower blood pressure
- If the current reading is consistently 160/100mmHg and up – the treatment will likely include both medications and suggested lifestyle changes
- Diet – the doctor will refer the patient to a dietitian to cut salt intake and switch to a low-fat balanced diet that includes plenty of fish and vegetables and helps in losing weight
- Exercise – the doctor will recommend moderate aerobic exercises to lower heart rate and lose weight
- Less alcohol and caffeinated drinks
- Quitting smoking
- Sleep – at least six hours a night
- If you’re a woman who plans to have a baby, consult with your doctor on how to control your blood pressure during pregnancy
Making these lifestyle adjustments, especially at an early stage of developing hypertension, may eliminate the need for medications. It may also help in preventing other health conditions, like obesity.
Medicines for high blood pressure
People with hypertension are usually prescribed with a combination of different medications. Patients under the age of 55 are normally recommended to use an ACE inhibitor or an angiotensin-2 receptor blocker (ARB), whereas patients aged 55 and older (or patients from an ethnic group at risk, like black residents of the Caribbean) are normally offered a calcium channel blocker.
These medications have some rare side effects like diarrhea, dizziness, lightheadedness, or weakness when standing up suddenly. There are many medications available, so if the side effects interfere with your daily life, consult with a doctor about replacing them.
Although the previous two forms of treatment are the most common and effective in treating hypertension, some people benefit from using other supplements. It is important to note that the scientific credibility of alternative therapies is yet to be proven. These include:
- Folic acid
- Fibers like blond psyllium and wheat bran
- Minerals, such as magnesium, calcium, and potassium
- Any supplements that increase nitric oxide or widen blood vessels (vasodilators), such as cocoa, coenzyme Q10, L-arginine or garlic
- Omega-3 fatty acids, found in fatty fish
All these supplements are recommended regardless of alternative treatment as ingredients in a healthy diet, but you can also take them as pills or capsules. However, you should consult a doctor before using supplements since some of them can interact with medications and endanger your health. While some may enhance the effect of the medications and their side effects, others would minimize it to no effect at all.
Living with the risk of hypertension
Managing stress levels is crucial when dealing with the risk of high blood pressure. Stress is an unavoidable part of life, but it must be managed to stay healthy. You can try:
- Breathing exercises
- Yoga and tai chi
Doctors also recommend adopting a “cleaner” lifestyle, free of cigarette smoke and other airborne chemicals that are making breathing uncomfortable. A “cleaner” atmosphere can be achieved by staying away from polluted areas and get out for fresh air during the workday. Try to avoid drugs and caffeine, exercise, drink plenty of water, and stick to a healthy diet.