Fraser Horton
Fraser Horton
Last Updated on March 2, 2021

The 2019 (COVID-19) pandemic has resulted in a significant increase in cannabis use, as well as other drug use, as people are trying to cope with the crisis any way they can.

And while regular cannabis users generally don’t experience many side effects as a result of being used to weed, first-time users may experience dizziness, shortness of breath, a green out, and even passing out.

Whether you vape it, smoke it in a joint, make edibles, or use a dab rig, fainting can happen to you while consuming marijuana. In this article, we’ll explain why that is so.

What’s a Cannabis Green Out?

Before we dive into why people pass out after consuming cannabis, we’ll first explain what greening out is. A “green out” is a physiological or psychological panic attack that can happen as a result of smoking weed, and it’s typically caused by smoking or ingesting too much cannabis in a short period of time. 

Symptoms of a green out include heart palpitation, anxiety, paranoia, sweating, nausea, and the sensation of a spinning room. In general, a green out is a brief experience, but it can sometimes cause vomiting and may even be accompanied by fainting.

Why Does Marijuana Make Some People Faint?

It doesn’t matter whether you’ve smoked a joint a thousand times as fainting can happen even to seasoned marijuana users. One moment you’re smoking a joint with your friends, and the next one you’re flat on the floor. If you’re a newbie, it can even happen after taking one hit of weed if the particular cannabis strain you’re smoking is pretty strong.

If you have underlying health conditions like low blood pressure or low blood sugar, it’s more likely that you may pass out during a smoking session. That’s because cannabis can lower both blood pressure and blood sugar.

One of the main cannabinoids found in cannabis, THC, can act as a vasodilatator in the body, which decreases blood pressure, and can lead to a blackout.

To avoid that, you may opt for a strain that is low in THC, but high in CBD, as it can limit the effects on the blood vessels, which, in turn, minimizes potential fainting.

Signs of Fainting From Recreational and Medical Marijuana

Even though marijuana use is very common nowadays, both recreationally and as an alternative medicine for treating conditions like ADHD, chronic pain, anxiety, as well as other conditions, there can be side effects to using it, like fainting.

Medical cannabis treatments generally focus on using CBD to treat and ameliorate most of these conditions, although strains with both THC and CBD are also used.  

If you’re a marijuana user, or even if you’re just trying marijuana for the first time, there are some telltale signs that you’ll most likely faint, and you need to recognize them before they happen.

You may start to feel dizzy, become nauseous, break out in a sweat, have a headache or blurred vision, and you may even have some trouble catching your breath. You may even look pale and unresponsive to the people around you. All of these signs indicate that you might be about to pass out.

If you’re experiencing some of these symptoms, it might be a good idea to find a place to sit down (and calm down) so you can enable your body to adjust to the THC and prevent fainting.

Causes for Blacking Out

Reasons for blackout moments among marijuana users can vary. One reason may be the result of the psychoactive cannabinoid tetrahydrocannabinol (THC) that expands blood vessels and decreases the blood pressure in the body (causes hypotension). As a result of this, the heart rate increases, as not enough blood gets to the brain, and it can cause you to pass out.

Another reason may be the cannabis consumption method, like smoking a joint, or using vaporizers and bongs, as these methods give the user a higher dose of marijuana in a small period of time. Moreover, fainting may also be related to the potency of weed. The more potent the bud, the higher the chances of fainting, especially in inexperienced smokers who are not prepared for such a strong cannabis effect.

Passing out can even be a result of drug interactions, underlying medical conditions, and even combining weed with other medication. A 2002 study revealed that people with cardiovascular diseases who are consuming high amounts of THC may be risking their lives by consuming weed as it can increase the catecholamine levels, carboxyhemoglobin, and postural hypotension. Those are all parameters related to conditions like diabetes, heart disease, and others.

How Common Is a Fainting Spell When Using Cannabis?

The underlying biological mechanisms that are involved in passing out are very complex. While sometimes the cause is evident, like having a lower blood sugar as a result of a hit of weed, at other times they’re unknown.

As to the question of how common can fainting spells occur, the answer is unclear. There’s a chance that it can only happen once and never again, but fainting as a result of smoking weed can also be a common occurrence for some users.  

In order to prevent potential fainting episodes when you do smoke weed, make sure you don’t smoke on an empty stomach, hydrate properly, check if weed may have some potential side effects when it’s combined with some medication you’re using, and take it easy. Keep in mind that you don’t need to rush the experiment and take a lot of hits at once.

Final Thoughts on Smoking Cannabis and Fainting

If you’ve been experiencing fainting spells and blood pressure changes, no matter if they’re weed-related or not, it’s always a good idea to consult your general practitioner or a healthcare provider to discuss why that may be the case. After all, for people with cardiovascular conditions, fainting may be a result of something more serious happening inside the body.

It’s also important to know and recognize the telltale signs that indicate a potential blackout to be able to prevent it. And if you feel it coming, make sure you take a seat until the symptoms pass, and stop smoking marijuana for the time being.


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