Key takeaways:
Common cannabis (weed) side effects include feeling high, a fast heart rate, and an increased appetite.
You may be able to lower these side effects by choosing cannabis products that are low in tetrahydrocannabinol (THC).
Using cannabis can also increase your risk for other mental and physical health problems, including heart disease.
Many people use cannabis, but that doesn’t mean it’s risk free. Just like other substances and medications, cannabis can cause short-term side effects. These typically go away when cannabis wears off. But cannabis is also linked to several mental and physical health problems, especially if you use high doses or large amounts over time.
Let’s take a closer look at some of the side effects and health problems linked to cannabis.
Side effects of cannabis
Below is a list of possible cannabis (weed) side effects. Most side effects are associated with tetrahydrocannabinol (THC). But a few are more likely with cannabidiol (CBD).
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Side effects of cannabis include:
Feeling “high” or “stoned”
Dizziness
Drowsiness
Red eyes
Dry mouth
Increased appetite
Fast heart rate
Diarrhea (with CBD use)
Short-term memory issues
Anxiety
Paranoia
Losing track of time
Feeling sad or depressed
Trouble thinking clearly
Trouble with coordination
Low blood pressure after standing up (orthostatic hypotension)
Psychosis, including hallucinations or delusions
Keep in mind: This isn’t a comprehensive list. There are many different types and strengths of cannabis, and everyone responds to cannabis differently. So, you may experience side effects that aren’t listed here. And some side effects are more likely if you consume cannabis along with other medications or substances.
Let’s take a closer look at three of these side effects in greater detail:
Feeling high
Fast heart rate
Increased appetite
Feeling high
The stoned or high feeling that can happen when you consume cannabis may be a desired effect for some people. But for others, such as those using cannabis for medical reasons, it may be an unwanted side effect. And it can be unpleasant for anyone if this side effect is more intense than expected.
The best way to avoid this side effect is to choose cannabis products that are low in THC. It’s also best to start with a small amount of cannabis and wait for it to kick in before consuming more. This gives you more control over how it affects you. Use extra caution with cannabis edibles, as it can take longer than expected to feel their effects.
If you find yourself feeling too high after consuming cannabis, try to stay calm. You may feel anxious or uncomfortable. But serious complications from consuming too much cannabis are rare. Find a distraction, such as listening to music or taking a walk if you feel you can do so safely. The intensity should lessen after an hour or so.
Fast heart rate
Cannabis can make your heart beat faster, especially if the product is high in THC. In most cases, this isn’t a serious issue, and your heartbeat will return to normal after a short time. But consuming cannabis frequently could raise your risk of a heart attack or stroke. And the risk is greater if you have a heart condition such as high blood pressure or an irregular heartbeat.
If you have a heart condition, it’s best to speak with a healthcare professional before consuming cannabis that contains THC. If at any point after consuming cannabis you have chest pain or trouble breathing, seek medical care right away.
Increased appetite
Another common THC side effect is an increased appetite, often referred to as “the munchies.” THC can make you feel hungry, even if you’ve recently eaten. It also enhances your desire for sweet and fatty foods. This can be a helpful side effect if you’re having trouble with nausea or don’t have an appetite. But for others, it may be bothersome or lead to unhealthy food choices.
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Lowering your THC dosage or choosing cannabis products with less THC can help prevent this side effect. It may also be helpful to keep nutritious snacks at hand, such as nuts, hummus, and fresh fruit.
Good to know: Even though cannabis can increase your appetite, there’s some evidence that those who consume cannabis actually weigh less on average than those who don’t. It’s not clear why this is the case. But it may help ease your mind if you’re concerned about weight gain from the munchies.
Health risks of cannabis
Cannabis is linked to mental and physical health problems too. These include:
Lung problems (due to smoking or vaping cannabis)
Increased risk of heart disease, heart attack, and stroke
Impaired brain development (with chronic use prior to age 25)
Liver problems (from CBD)
Increased risk of severe mental illness, including schizophrenia
Let’s go into more detail on a few of these:
Cannabis hyperemesis syndrome
Heart problems
Cannabis use disorder
Mental health concerns
Cannabis hyperemesis syndrome
Cannabis is known for its anti-nausea effects. But it can also cause repeated cycles of vomiting for some people, known as cannabis hyperemesis syndrome (CHS). CHS happens most often after large doses of THC or consuming large amounts of cannabis over a long period of time.
If you experience severe or non-stop vomiting after consuming cannabis, you may be experiencing CHS. Taking a hot shower or applying a layer of capsaicin cream to your stomach may help. But if you’re unable to stop vomiting on your own, it’s best to seek medical care. CHS can lead to dehydration, which can be dangerous if not treated properly.
Consuming lower amounts of THC and taking frequent breaks from using cannabis may help lower your risk of CHS, but there’s not a guaranteed way to prevent it. Some people may be more likely to develop CHS based on inherited traits, but more research is needed to know for sure. Once you’ve developed CHS, the only way to avoid it is to stop consuming cannabis.
Increased risk of heart problems
The regular consumption of cannabis is associated with an increased risk of heart disease, heart attack, and stroke. A 2024 study of over 400,000 people showed that cannabis use is associated with heart problems. And the more often it’s consumed, the greater your risk.
If you have a history of heart problems, talk to a healthcare professional before consuming cannabis for any reason. And it’s best to keep your cannabis consumption to a minimum to limit this risk, unless instructed otherwise by a medical professional.
Cannabis use disorder
Cannabis is a controlled substance, which means it carries a risk of dependence and misuse. It’s estimated that 1 in 5 people who consume cannabis may develop cannabis use disorder. And the risk may be higher for people who use cannabis daily or weekly.
Cannabis use disorder is defined as having two or more of the following:
Consuming cannabis in larger amounts or more often than intended
Being unable to control cannabis use
Spending a lot of time getting, using, or recovering from cannabis
Experiencing strong cravings to consume cannabis
Having problems at home, school, or work caused by consuming cannabis
Continuing to consume cannabis, even when it’s causing legal, mental, or physical problems
Needing to use more cannabis or a stronger type to get the same effect
Consuming cannabis to avoid withdrawal symptoms
Using cannabis in high-risk situations (like while driving)
Missing important activities to use cannabis
The risk for cannabis use disorder goes up if you have a history of substance misuse or consume cannabis before the age of 18. Genetics and other social or health issues can also make it more likely.
If you’re concerned about cannabis use disorder, speak to a loved one or a healthcare professional. They can help you find the support and treatment you need.
Other mental health issues
Several studies have shown an association between consuming cannabis and an increased risk for certain mental health issues, such as schizophrenia. But it’s not clear if cannabis actually causes schizophrenia, or if people living with schizophrenia are simply more likely to self-medicate with cannabis.
Regular cannabis use is also associated with an increased risk of depression, anxiety, and suicidal thoughts in some people. Again, there’s not clear evidence that cannabis actually causes these problems, but it’s still good to be aware of the possibility.
If you have a history of mental health problems, cannabis may worsen your symptoms. So, it may not be a good choice for you. Talk to a healthcare professional first to see if cannabis may be a safe option for you. If at any point you or a loved one notice a concerning change in your behavior during or after consuming cannabis, seek medical care.
Frequently asked questions
A fast heart rate caused by cannabis usually goes away on its own with time, as the cannabis effects wear off. And the truth is that there’s no way to make these effects go away any faster. You just need to wait it out.
While you wait, try to keep yourself calm and comfortable. Sit or lie down somewhere quiet, drink some water, and take slow breaths. But you should call 911 right away if you:
Are experiencing chest pain
Feel like you might lose consciousness
Are having trouble breathing
How long cannabis’s effects last depends on a few things, like how you’re consuming it. For an inhaled dose (like from smoking), it might take a few hours for the effects to wear off. But effects from an edible might last much longer. It also depends on the dose and strength of the cannabis that you’ve used.
Yes, if you consume cannabis often, you may experience withdrawal symptoms if you stop consuming it abruptly. Normally, these symptoms peak in the first week after you stop using cannabis, but they can last for 2 weeks or longer for some people. The good news is that unlike other substances, cannabis withdrawal isn’t likely to be dangerous or harmful to your health.
Most people can manage these symptoms on their own and return to feeling normal quickly. But talk to a healthcare professional in these cases:
The symptoms aren’t improving.
You have more serious symptoms, such as stomach pain, sweating, or shakiness.
They can help manage your symptoms safely.
A fast heart rate caused by cannabis usually goes away on its own with time, as the cannabis effects wear off. And the truth is that there’s no way to make these effects go away any faster. You just need to wait it out.
While you wait, try to keep yourself calm and comfortable. Sit or lie down somewhere quiet, drink some water, and take slow breaths. But you should call 911 right away if you:
Are experiencing chest pain
Feel like you might lose consciousness
Are having trouble breathing
How long cannabis’s effects last depends on a few things, like how you’re consuming it. For an inhaled dose (like from smoking), it might take a few hours for the effects to wear off. But effects from an edible might last much longer. It also depends on the dose and strength of the cannabis that you’ve used.
Yes, if you consume cannabis often, you may experience withdrawal symptoms if you stop consuming it abruptly. Normally, these symptoms peak in the first week after you stop using cannabis, but they can last for 2 weeks or longer for some people. The good news is that unlike other substances, cannabis withdrawal isn’t likely to be dangerous or harmful to your health.
Most people can manage these symptoms on their own and return to feeling normal quickly. But talk to a healthcare professional in these cases:
The symptoms aren’t improving.
You have more serious symptoms, such as stomach pain, sweating, or shakiness.
They can help manage your symptoms safely.
The bottom line
Many people use cannabis for medical and recreational reasons. Cannabis can cause side effects like feeling high, having an increased appetite, and experiencing a fast heartbeat. Using cannabis is also linked to other mental and physical health problems, including heart disease.
If you choose to consume cannabis, consider talking with a healthcare professional first. They can help you understand the risks and potential medical benefits. And if you do use cannabis, consider putting limits on how much you use, as well as sticking with products that are lower in tetrahydrocannabinol (THC).
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References
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Connor, J. P., et al. (2022). Clinical management of cannabis withdrawal. Addiction.
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Le Foll, B., et al. (2024). Cannabis use disorder: From neurobiology to treatment. The Journal of Clinical Investigation.
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National Institute on Drug Abuse. (2024). Cannabis (marijuana).
Shah, S., et al. (2021). Association of marijuana use and cardiovascular disease: A behavioral risk factor surveillance system data analysis of 133,706 U.S. adults. The American Journal of Medicine.
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Stix, G. (2023). Heavy cannabis use linked to schizophrenia, especially among young men. Scientific American.
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