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What Does Cannabis Do To Your Body?

cannabis leaves with a black background

There are two main components of cannabis that affect the human body, THC and CBD. Of the two, THC is an intoxicant. This is the part of cannabis that produces the high. By contrast, CBD does not affect your mental state. Because of the legal status of cannabis around the world, there is still a great deal we do not understand about both THC and CBD.

Thankfully there are some things we know cannabis does to the body including the following:

Release of dopamine in the brain
Increased heart rate
Dilation of blood vessels
Lower intraocular pressure (lower pressure in your eyes)

The release of dopamine in the brain explains the feelings of happiness associated with cannabis use. Dopamine is a “feel good” chemical that is naturally produced in the brain. When a large amount is released you tend to feel high.

The increase in heart rate will not usually harm a healthy person but it can be very dangerous to someone with a heart condition or other cardiovascular disease.

Dilating blood vessels means the vessels expand so they can carry more blood. This helps explain why cannabis users eyes look bloodshot. You can see the veins more clearly.

Finally, the lower intraocular pressure means the pressure in your eyes decreases slightly. This can be helpful for people with glaucoma as it is a condition that increases pressure in your eyes.

Cannabis is also believed to have the following effects:
Suppressed immune system
Increased appetite
Relief of pain and inflammation
Reduction in nausea and vomiting

Suppressing the immune system means someone using cannabis will be more susceptible to illness. It also means that cannabis could be used by someone with an autoimmune disease to help manage their condition.

Cannabis also increases peoples appetite. This helps explain the feeling of hunger many users get after ingesting the drug. The boost in appetite combined with cannabis being able to reduce nausea and vomiting means that it is often used by cancer patients whose medication makes it hard for them to eat without vomiting.

By suppressing nausea and vomiting, cannabis can also pose a risk to people who drink alcohol. If you drink and use cannabis at the same time, you could increase your risk of alcohol poisoning. This is because your body naturally induces vomiting if you drink too much. It may be unable to do so if you are also using cannabis.

Finally, cannabis has been shown in some studies to reduce pain and inflammation. This could have implications for its use in future medicine but it should not be considered a substitute for conventional pain relievers.


In addition to the effects of cannabis, we should note that there are some negative effects if you ingest cannabis by smoking it. Smoking cannabis can irritate the lungs and increase your risk of cancer. This is not due to the THC or CBD, but because you are inhaling smoke. Smoking anything will produce these effects.

If you are struggling with cannabis abuse, Help Me Stop has treatment available. Our experts can offer treatment around work, school or other commitments. Contact us today to learn more.

If you have a problem with alcohol or drugs, or know someone who does, contact us for free, confidential advice now on 0208 191 9191 or jump onto Live Chat/email us directly at enquiries@helpmestop.org.uk .

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