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Using cannabis can harm your physical and mental health.

Just as with other substances, consuming cannabis can harm your physical and mental health. Be informed about the effects of cannabis and how to protect yourself and the things that are important to you.

What is cannabis?
Cannabis is known by many names including marijuana, weed, hash—and others. Cannabis refers to the greenish or brownish material that  comes from the dried flowering tops and leaves of the plant, Cannabis sativa or Cannabis indica. 




How does cannabis affect my physical health?
Using cannabis can have many short and long-term effects, including:

  • Coughing, wheezing, and shortness of breath.
  • Lung infection or bronchitis.
  • Decreased blood pressure (risk of fainting or passing out).
  • Increased heart rate (higher risk of heart attack).
  • Hyperemesis syndrome (uncontrollable vomiting).
  • Poor coordination and slow reaction time.
  • Increased risk of injury (e.g., motor vehicle collision, falls).
  • Some forms of cancer.

Is cannabis safer than tobacco?
Cannabis smoke has many similar carcinogens, toxins, and irritants to those found in tobacco smoke and known to cause cancer, heart disease and respiratory diseases like bronchitis. Cannabis is not harmless just because it’s more “natural”.


How does cannabis affect my brain and mental health?
Cannabis use can have unwanted or unpleasant psychological effects such as:

  • Confusion and difficulty concentrating.
  • Anxiety, fear, or panic.
  • Psychotic episodes of paranoia, delusions, or hallucinations.
  • Drowsiness.

Is cannabis addictive?
Yes. Regular, daily, and heavy cannabis use can lead to dependence and in extreme cases, addiction in the form of Cannabis Use Disorder. In fact, about 1 in 6 teenagers and 1 in 11 adults who use cannabis will develop an addiction. When someone stops using cannabis after regular or heavy consumption they may also experience withdrawal symptoms that lead people to keep using it to offset symptoms of:

  • Irritability.
  • Trouble sleeping.
  • Dysphoria (state of general unhappiness), restlessness, dissatisfaction, or frustration.
  • Depression or anxiety.
  • Cravings or changes in appetite and weight loss.

Can you overdose on cannabis?
Yes. While cannabis overdose does not happen in the same way as opioids or other drugs, there is still a risk of overconsumption which can cause high levels of anxiety, fear or panic, and psychotic episodes of paranoia, delusions or hallucinations. In addition, Hyperemesis Syndrome involving uncontrollable vomiting may occur.

When consuming cannabis purchased or received from an unreliable or unregulated source, the 
risk for overdose from other substances is also higher. Substances such as opioids, cocaine, methamphetamine, MDMA, LSD, or household chemicals can be found in unregulated or “black market” cannabis causing a higher risk of overdose from non-cannabis substances. 


In the case of over consumption or unintentional ingestion of cannabis call the Ontario Poison Centre (1-800-268-9017) or 911 immediately.  

If you or a loved one is struggling with physical dependence or addiction to cannabis or other drugs, you can get help from:

Connex Ontario – Telephone or Web Chat Service
(24 hours/7 days a week) 
Addiction, Mental Health, and Problem Gambling Services 1-866-531-2600 |
Free, confidential and anonymous information and referral to drug and alcohol treatment services across Ontario. Services available in English and French, and provided in over 170 languages on request.

Windsor-Essex County Health Unit 
Visit the website to find local treatment options in Windsor and Essex County.

Kids Help Phone (24 hours/7 days a week)
1-800-668-6868 |
Safe, private, and non-judgmental phone counselling, web counselling and referral service for children and youth. Service available in English and French.


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