Medically Reviewed by
Jason Crawford

Article Last Updated on January 3, 2023

As the legalization of cannabis increases all over the US, so does the recreational use of marijuana. In the past years, about 15 states have legalized recreational cannabis use, and others are expected to follow in the near future. Cannabis users are expected to reach 46.6 million people by 2025, according to an analysis by Statista.

Whether you like to vape, smoke a bong, consume weed brownies, use tinctures or other cannabis products, cannabis use does affect your body in more ways than one. Excessive use of the cannabis plant by cannabis users can have a negative impact on public health which is why so much focus is put on informing the public of the effects of using both recreational and medical marijuana.

If you’d like to know how vaping, smoking, or consuming weed in any form affects your body, stick with us. We’ll give you an overview of the physical and mental health effects that happen as a result of cannabis use, as well as give you information about the long-term effects of weed consumption.

Cannabinoids in Marijuana (THC vs CBD)

The marijuana plant has over 60 cannabinoids, out of which the most popular active ingredients are tetrahydrocannabinol (THC) and cannabidiol (CBD). They’re responsible for most of marijuana’s effects on users, including the psychoactive, anti-inflammatory, and therapeutic effects.

For humans to be able to feel the effects of weed, we need to thank our endocannabinoid system. The ECS is made up of endocannabinoids, cannabinoid receptors, and the enzymes that degrade the consumed cannabinoids, which is why it gets affected when we consume weed. This system is also in charge of our short-term memory, appetite, metabolism, and other functions. 

The Effects of Weed on Your Body

After the cannabinoids pass through the cannabinoid receptors in the ECS, users start feeling the effects of cannabis. To give you all the necessary information on how weed affects the body, we’ll go over both the physical and mental effects that weed has on users.

How Marijuana Affects Physical Health

Weed affects a few of the key systems in the body, including the:

  • Respiratory system;
  • Circulatory system;
  • Central nervous system;
  • Digestive system.

Respiratory System

Marijuana smoke consists of harmful chemicals that may irritate the bronchial passages. Therefore, cannabis users who consume high amounts of weed and do so often are more likely to produce phlegm and cough, as well as have an increased risk for getting bronchitis or a lung infection.

Some sources claim that marijuana smoke, similar to tobacco smoke, may cause lung cancer as a result of the carcinogens present in weed. However, the National Institute on Drug Abuse (NIDA) has debunked this myth, and there are no sufficient studies which support the claim that cannabis can cause lung cancer. However, even though studies don’t view cannabis as a cancer-causing plant, users should keep in mind to use it responsibly (and in moderation).

Circulatory System

No matter what your chosen weed consumption method is, the cannabinoids from weed will eventually end up in the bloodstream. After entering the bloodstream, they can increase your heart rate, and may even cause a heart attack.

On the other hand, the active ingredients in weed, THC and CBD, may help reduce cancerous tumors and help patients with a cancer diagnosis by stopping the growth of blood vessels that feed the tumors. This research hasn’t been backed up by a lot of studies since it’s fairly new, so researchers are focusing on finding out more before they recommend weed as a treatment option for cancer.

Central Nervous System

It’s no secret that the effects of marijuana mainly affect the parts of the brain that control decision making, learning, attention, memory, emotions, coordination, reaction time, and others. For that reason, marijuana use can help patients suffering from chronic pain, seizures, and other conditions because THC affects neurotransmitters like norepinephrine and dopamine – which results in euphoria, heightened senses, and relaxation.

On the other hand, consuming weed affects the hippocampus, the part of the brain responsible for forming new memories, which is why people under the influence of cannabis find it hard to form new memories. Moreover, cannabis use also affects coordination and balance, which makes it difficult for marijuana users to drive after consuming weed.

Digestive System

Weed is often a treatment option for patients who are doing chemo since it improves eating habits and causes a case of the munchies.

How Marijuana Affects Psychological Health

Marijuana has many potential psychological effects, which is why patients with mental health disorders should seek medical advice if they’re thinking about using marijuana as a treatment option.

Weed’s effects on mental health:

  • Weed causes psychoactive effects in users, and the release of dopamine gives you a satisfying high;
  • Weed may increase or decrease symptoms in patients suffering from depression or anxiety;
  • Weed can impair your judgment and make you have delayed reactions (which is why you shouldn’t drive after smoking);
  • Weed may cause symptoms of withdrawal after long-term use;
  • Weed can impair your short-term memory;
  • Weed can trigger schizophrenia or paranoia in users with genetic predispositions;
  • Weed may cause addiction.

Medical Marijuana and Its Effects

Weed has been used as a treatment option for conditions such as Lennox-Gastaut syndrome and Dravet syndrome. The FDA has approved a CBD medication, Epidiolex, intended to treat these conditions specifically. Epidiolex may cause side effects like fatigue, decreased appetite, sleepiness, insomnia, and diarrhea. Medical use of cannabis should only be an option after consultation with a licensed physician.

How Marijuana Affects You in the Short-Term vs the Long-Term?

Cannabis use may cause short-term and long-term negative effects and health problems in users. Some of them are listed below.

Short Term Effects 

  • Short-term memory problems;
  • Anxiety, paranoia, hallucinations;
  • Impaired coordination and lowered reaction time which can cause problems while driving or operating heavy machinery;
  • Sexual performance issues for men.

Long-Term Effects

Marijuana use may pose some health risks, including:

  • Breathing problems as a result of marijuana smoke irritating the lungs.
  • Vaping may cause acute lung injury.
  • Problems with the development of a child (during and after pregnancy).
  • Cannabis use can lead to a higher risk of impaired brain development and a loss of IQ in young adults and adolescents.
  • Marijuana use can increase your chances of getting a heart attack as a result of an increased heart rate.
  • Long-term cannabis use may worsen mental illnesses like depression and anxiety.
  • Cannabis use may trigger schizophrenia or psychosis in patients with a predisposition for those illnesses.

Final Thoughts on the Effects of THC on the Body

While smoking marijuana can provide you with a number of positive health benefits, like treating chronic pain, epileptic seizures, help with nausea, and other conditions, substance use may also be harmful to your health.

Long-term cannabis drug use may result in addiction which may be a gateway to using other drugs and opioids. For users with underlying heart and neurological conditions, weed may worsen their symptoms and even cause a heart attack or trigger schizophrenia and psychosis. Finally, long-term cannabis users often have a problem with coughing and phlegm production, so smoking marijuana isn’t recommended for people with chronic illnesses like bronchitis.

If you’d like to learn more about the medical benefits of cannabinoids, follow the National Institutes of Health (NIH) and read about the newest research regarding cannabis and cannabinoids. 

A passionate advocate for the benefits of cannabis. Fraser Horton, who has a background in botany and a strong love of nature, has spent years researching how cannabis affects the body and mind. He established Leaf Nation in 2020, where he has devoted himself to educating people about the legalisation of marijuana and its safe and responsible use. Fraser is committed to highlighting cannabis’ potential for improving wellness and working to dispel the stigma associated with its use.


The information presented on this page is provided as a public service to aid in education and is derived from sources believed to be reliable. Readers are responsible for making their own assessment of the topics discussed here. In no event shall Leaf Nation be held reliable for any injury, loss or damage that could happen if using or abusing drugs.