Compare
Compare to the live page
Archived snapshot
Health effects of cannabis - Canada.ca
2025-04-18T14:21:53.949Z · legacy-hc-2025-04-21
ID 165113
Original URL ↗Live page
Live fetch
2026-01-31T17:31:18.017Z
Status: 200 · Type: text/html;charset=utf-8 · Bytes: 26619
Independent archive · Descriptive changes only; the live page is not archived. Cite the snapshot (/cite).
1 sections changedMain contentChange ratio: 0%+0 / -1 lines1 sections changed
Health effects of cannabis
Effects can be felt within seconds to minutes of smoking, vaporizing or dabbing cannabis. These effects can last up to 24 hours.
If you eat or drink cannabis, these effects can occur within 30 minutes to 2 hours and can last up to 24 hours.
On this page
Short-term health effects
Long-term health effects
Effects on different age groups
Health effects during pregnancy and breastfeeding
Potential therapeutic uses of cannabis
Short-term health effects
The flowers and leaves of the cannabis plant are used for their ability to cause effects on the mind, including:
feeling high (euphoria)
a sense of well-being
relaxation
heightened sensory experiences:
sight
taste
smell
sound
While cannabis may make you feel relaxed and happy, your body and brain may also experience effects that are:
negative
unwanted
unpleasant
Some of the short-term effects on your brain can include:
confusion
sleepiness (fatigue)
impaired ability to:
remember
concentrate
pay attention
react quickly
anxiety, fear or panic
Short term effects on your body can also include:
if smoking, damaged blood vessels caused by the smoke
decreased blood pressure, which can cause people to faint
increased heart rate, which can be dangerous for people with heart conditions and can lead to an
increased risk of heart attack
Cannabis use can also result in psychotic episodes characterized by:
paranoia
delusions
hallucinations
Long-term health effects
Long-term effects develop gradually over time, with daily or near-daily (weekly) use that continues over:
weeks
months
years
The long-term effects of cannabis on your brain can include an increased risk of
addiction
. Long-term cannabis use can also harm your:
memory
concentration
intelligence (IQ)
ability to think and make decisions
Effects appear to be worse if you:
start using early in adolescence
use frequently and over a long period of time
These
effects can last from several days, to months or longer
after you stop using cannabis. They may not be fully reversible even when cannabis use stops.
Other long-term effects of smoking cannabis are similar to the effects of smoking tobacco. These effects can include risks to lung health, such as:
bronchitis
lung infections
chronic (long-term) cough
increased mucus buildup in the chest
Effects on different age groups
Depending on your age, there are various factors to consider when deciding to use cannabis. Learn more about how cannabis affects:
youth aged 13–17 years
young adults aged 18–25 years
Health effects during pregnancy and breastfeeding
Just like with tobacco and alcohol, a pregnant woman or new mother's use of cannabis can affect her fetus or newborn child.
The substances in cannabis are carried through the mother's blood to her fetus during pregnancy. They are passed into the breast milk following birth. This can lead to health problems for the child.
Cannabis use during pregnancy can lead to lower birth weight of the baby. It has also been associated with longer-term developmental effects in children and adolescents, such as:
decreases in:
memory function
ability to pay attention
reasoning and problem-solving skills
hyperactive behaviour
increased risk for future substance use
Learn more about
the health effects of cannabis during preconception, pregnancy, and breastfeeding.
Potential therapeutic uses of cannabis
There is some evidence of potential therapeutic uses for cannabis or its component chemicals (cannabinoids).
Health Canada has
information for health care professionals
and for
authorized patients
on the
use of cannabis and cannabinoids for medical purposes
. This includes information on:
potential therapeutic uses
dosing
warnings
adverse effects
About cannabis
Cannabis and mental health
Cannabis impairment and safety risk
Driving while impaired by a drug
Minimizing your risk when smoking, vaping and dabbing
Thinking about using cannabis before or during pregnancy?
Thinking about using cannabis while parenting?
What is chronic pain
Page details
Date modified:
2024-03-25