Why Does Marijuana Make You Dizzy?

Let's dive into the science behind the plant

Although marijuana is often promoted as having few negative side effects, anyone who has ever thrown a whitey or greened out will disagree. The fact is that dizziness is a common side effect of cannabis, especially for inexperienced users or when it is combined with alcohol.

Although feeling dizzy is something which can affect all marijuana users from time to time, it is usually mild, short-lived, and no cause for concern. So why can marijuana make you dizzy? Let’s take a look at the science that explains this common problem.

Marijuana and Dizziness

Marijuana can make you dizzy, and this side effect is more common than you might think. One study on marijuana smoking and dizziness found as many as that 60% of its participants experienced moderate to severe dizziness after smoking marijuana.

The small-scale study, published in 1992, took ten healthy, male volunteers who had previously used cannabis but were drug-free for at least three months. The participants had their blood pressure, heart rate, and cerebral blood flow measured in a reclining and standing position, both before and after smoking a high-potency joint or a placebo on two separate laboratory visits.

Six of the ten participants reported moderate to severe dizziness after smoking the genuine marijuana, but not the placebo. The authors of this controlled study found that the participants who had experienced moderate dizziness had reduced cerebral blood flow after smoking, and those who had severe dizziness had markedly reduced cerebral blood flow and blood pressure.

Changes in circulation and blood pressure appear to be the primary reason why marijuana can make you dizzy, especially when you stand up. This condition is called postural hypotension or orthotic hypotension, to give it its proper medical name.

What is Postural Hypotension?

When you stand up, gravity causes blood to flow downwards from your chest to the blood vessels below your diaphragm. This shift reduces the amount of blood returning to and filling your heart and causes your blood pressure to fall.

Under normal circumstances, this activates baroreceptors in your major arteries. These are receptors which are specifically designed to detect changes in your blood pressure and initiate a response to normalize it.

In the case of low blood pressure, these baroreceptors trigger an increase in heart rate and cause your blood vessels to constrict. Blood is then pumped more quickly and has more resistance in the veins, thus returning your blood pressure to its normal levels. This response is known as baroreflex, and it plays an essential role in maintaining healthy circulation.

In certain circumstances, this response can be interrupted. This interruption could be due to a failure of the baroreflex system, organ dysfunction, certain medications, dehydration, and of course, marijuana.
When your blood pressure cannot stabilize itself after you stand up, this causes postural hypotension to occur. Postural hypotension temporarily decreases the blood flow and oxygen supply to your brain resulting in many different symptoms including:

  • Light-headedness
  • Dizziness
  • Weakness
  • Confusion
  • Headaches
  • Fainting

In some cases, postural hypotension can also cause palpitations, tremors, and nausea as your body tries to overcompensate for the sudden drop in blood pressure. These symptoms will sound all too familiar to anyone who has ever paid the price for smoking too much cannabis too fast or mixing it with alcohol.

How Does Marijuana Affect Your Blood Pressure?

Your blood pressure is monitored and regulated in several different ways, including by the baroreceptors in your blood vessels and hormones secreted by your kidneys. Many scientists also believe that the endocannabinoid system plays a crucial role in blood pressure and heart rate regulation, which is why cannabis can have such a powerful effect on your circulation.

The endocannabinoid system consists of receptors known as CB1 and CB2 receptors, and molecules called endocannabinoids. These are chemicals secreted by your body which are responsible for keeping you in a state of internal balance called homeostasis. They do this by binding with the CB1 and CB2 receptors to trigger a variety of physiological responses.

One of the best-studied endocannabinoids is called anandamide. This chemical has been found to relax and dilate the blood vessels, causing blood pressure to fall. One of the compounds in cannabis, Δ9-tetrahydrocannabinol (THC) has been found to have similar effects. In the body, THC binds with CB1 receptors, meaning that like anandamide, it can cause your blood vessels to dilate rapidly and your blood pressure to fall.

Smoking marijuana has been shown to have the short-term effects of increasing heart rate and decreasing blood pressure, and in high doses, it can lead to postural hypotension. After just a day or two of repeated exposure, tolerance develops and the chances of postural hypotension decrease. This tolerance is the reason why inexperienced or occasional cannabis users are more likely to feel dizzy than those who smoke every day.

What to do if Marijuana Makes You Dizzy

Feeling dizzy after smoking marijuana is a common problem, but there are plenty of things you can do to help yourself overcome this side effect.

Know Your Limits

Dizziness usually happens after smoking too much too fast, so the best way to avoid it is by starting slow. Taking this precaution is especially important if you are new to cannabis, only smoke occasionally, or have had a break of a few days or more.

If you are smoking, take one or two small puffs first and gradually build up to longer, deeper hits. If you prefer edibles, you will need to be even more cautious. When weed has to pass through your digestive system, it takes longer to kick in, so avoid the temptation to think “nothing’s happening, I’ll eat another…” or you will almost certainly regret it. Allow a couple of hours to let your chosen edible take full effect before deciding to go in for number two.

Stand up Slowly

Standing up too quickly can cause your blood pressure to drop suddenly leading to postural hypotension and dizziness. The best way to combat this is by standing up as slowly as you can. You could also try gently stretching and moving your arms and legs to get your circulation going before you get up. Simple, but effective!

Stay Hydrated

Dehydration can lead to postural hypotension as not enough water in your body means not enough volume in your blood. Make sure you consume enough water or other drinks alongside your marijuana to keep your fluid levels up and your blood pressure stable.

As a guideline, you should aim to drink two liters, or three and a half pints, of water every day. If you are a marijuana user, you may want to increase this slightly and drink a glass or two before standing up to prevent dizziness.

Keep Snacks Handy

A combination of low blood pressure and low blood sugar is bound to cause dizziness, so always have some snacks available when you are high. Sweet snacks will help to increase blood sugar and salty snacks will increase blood pressure, so combining the two should help.

If you would prefer to avoid snacking, try using rehydration salts or sports drinks which will help to rebalance your blood chemistry and stop you from feeling dizzy.


Exercise is probably the very last thing on your mind when you are dizzy and high, but gentle movement can help to improve your circulation and get the blood flowing to your brain. Try exercises which cause your abdominal muscles to contract and encourage blood to return to your heart. These include toe raises, leg elevations, and slowly marching on the spot.

Stay Calm

Greening out can be a scary experience, especially when it happens for the first time. If you feel dizzy or faint, it is important not to panic as this will only make things worse. If you feel dizzy after standing, you should sit back down, take a few deep breaths and stand up again more slowly. You can also use a wall to stabilize yourself if you feel like you might fall.

Remember that marijuana can often cause dizziness and, in most cases, there is no need to be concerned.

Try a Different Strain

Different strains of cannabis contain varying levels of THC and other cannabinoids such as cannabidiol (CBD). Certain strains are known to be higher in THC and give more cerebral effects, while others are higher in CBD and may be more useful for medicinal purposes.

If you regularly suffer from dizziness while high, try switching to another strain with a higher CBD content. The increased levels of CBD should help to counteract the effects of the THC and reduce the likelihood of feeling dizzy.

Final Thoughts: Why can Marijuana Make You Dizzy?

Although cannabis generally has a low risk of adverse effects, it can cause dizziness in some people, especially those who have not built up a tolerance to its effects. This reaction is due to the way that THC affects your blood pressure, causing it to fall suddenly.

If you feel dizzy after smoking, there is probably no reason to worry. This side effect is common and will usually wear off fairly quickly. However, if you are finding that you frequently feel dizzy or faint when high, or if you feel dizzy even when you haven’t smoked, talk to your physician to find out why and what you should do to help.