Short- and Long-Term Health Effects of Cannabis Use

Published on January 26, 2023 | Last updated October 17, 2024

Cannabis is a complex plant, and individual experiences can differ greatly. Nobody wants to have an uncomfortable experience, and cannabis education can be key to reducing the possible long- and short-term effects of cannabis consumption. The effects you may experience — positive or otherwise — depend on how often you consume cannabis, how much you use, what kinds of products you use and their THC potency, on top of other individual factors.

Below we discuss a variety of effects cannabis can have. These are mainly the effects of consuming the cannabinoid known as THC, although other cannabinoids, like non-intoxicating CBD, can also have effects. Some researchers suggest that many cannabinoids interact with one another to produce an overall effect, referred to as the “entourage effect.”

What are the short-term effects of cannabis use?

The short-term health effects of cannabis use can include:

• feeling relaxed
• a heightened sensory experience, involving your sight, taste, smell and/or hearing
• feeling “high” or euphoric
• feeling confused
• fatigue or sleepiness
• trouble with memory or concentration
• loss of inhibition or motivation
• increased appetite
• decreased blood pressure
• increased heart rate (particularly for people with heart conditions or high blood pressure)

Short-term mental health effects

The temporary mental health effects of cannabis consumption can include anxiety, fear, restlessness or panic.

Although less common, and most often affecting frequent consumers or those who consume large amounts of THC, cannabis use can lead to psychotic episodes, which is why it’s always important to consider your family history and individual risk profile before consuming cannabis. Psychotic episodes can involve:

• paranoia
• hallucinations
• delusions

If you or your family have a history of mental health conditions, abstaining may be a good option for you. If you are younger than 25, you may also want to consider delaying use. If you do choose to use cannabis, consider using it less often or choosing low-THC products.

Explore the complex connection between regular cannabis use and mental health.

What are the long-term effects of cannabis use?

Most of the long-term effects of cannabis impact daily or near-daily consumers who have used cannabis for a long time. The effects can include:

• long-term impact on memory and concentration
• risk of developing cannabis use disorder or problematic use patterns that interfere with work, school or family and friends

If smoking is the method of cannabis consumption, long-term health impacts can include:

• bronchitis
• lung infections
• chronic (long-term) cough
• increased mucus buildup in the chest
• potential impacts on the brain for adults and youth
• damaged blood vessels

Although less common, cannabis hyperemesis syndrome is also a potential long-term risk, characterized by cyclical vomiting, severe nausea, sweating, abnormal thirst and abdominal pain. It’s thought to be caused by heavy and long-term cannabis use, and typically resolves when consumers abstain from cannabis. If you are experiencing any of the above symptoms and think they may be related to cannabis use, reach out to your healthcare provider.

Long-term mental health effects

Although cannabis use can have temporary, short-term impacts on mental health, regular cannabis consumption can increase the risk of developing long-term mental health disorders, including schizophrenia. This risk is greatest for those who have a family history of schizophrenia.

Cannabis and pregnancy or breastfeeding

While many pregnant people consider consuming cannabis for nausea, it’s important to understand what we know (and what we don’t know) about cannabis and pregnancy. Consuming cannabis is not recommended while pregnant, and it also carries risks while trying to conceive and/or breastfeeding.

According to Health Canada:

• Cannabis can decrease blood pressure, which can cause dizziness or fainting in pregnant people.
• Those who consume cannabis while pregnant slightly increase their risk of anaemia.
• Cannabis consumption may also increase fatigue, forgetfulness, anxiety or paranoia.

Find out more about the potential effects of cannabis on pregnancy and breastfeeding.

Health effects of cannabis based on your individual factors

The effects you may experience with cannabis consumption are also related to individual factors. These factors include:

• your age (youth and young adults have increased likelihood of short- and long-term health impacts)
• your sex
• your history of cannabis use
• the frequency of your cannabis use
• the types of products used and THC potency
• your family history of mental health issues

These factors are all critical to understanding the potential outcomes and experiences you may have with cannabis consumption.

While research is still uncovering some of these short- and long-term impacts of cannabis use, there is evidence to support two identifiable risk factors: starting consumption early in adolescence (before age 14) and frequent and heavy use, specifically with high-potency THC products over a long period of time.

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