Until recent years, research into the health effects of cannabis use has been limited by both policy and funding. More research will always be needed to fully understand the impact of cannabis on health. However, there are some common findings that link cannabis use with a number of short- and long-term health effects.
Short-Term Health Effects
Recent cannabis use (defined as use within the last 24 hours) has immediate, yet temporary, effects on health, which may include:
Distorted awareness of distance and time
Faster heart rate
Impaired decision-making, coordination, movement, and reaction time
Increased blood pressure
Trouble with thinking, paying attention, and remembering
Long-Term Health Effects
Some studies suggest that frequent and regular cannabis use may impact brain function in adults and youth, compared to people who do not use cannabis. The developing brains of children and teenagers are especially at risk to the harmful effects of cannabis.
Cannabinoid Hyperemesis Syndrome
Research on cannabinoid hyperemesis syndrome (CHS) is limited and the causes of CHS are not fully understood. However, some studies suggest that using cannabis often and over a long period of time may increase the risk of developing CHS. CHS may cause symptoms such as repeated nausea and vomiting. People with CHS may also experience abdominal pain after cannabis use. The only known way to prevent and cure CHS is to stop using cannabis.
Cannabis Use Disorder
Cannabis Use Disorder (CUD) is a health condition caused by cannabis use. Risk of developing CUD may increase if cannabis use begins in youth, or when used more frequently at any age.
Although more research is needed to better understand the impact of cannabis use on the heart, some research suggests that long-term cannabis use can lead to higher risk of heart attack, heart disease, and stroke.
Long-term cannabis use has been linked to depression, social anxiety, and thoughts of self-harm. Some research suggests that using cannabis often may increase the risk of developing mental disorders (for example, psychosis) and make the symptoms of existing mental disorders worse.
When you smoke cannabis, you breathe in harmful chemicals. Smoking cannabis on a regular basis has been linked to chronic bronchitis, wheezing, exercise-induced shortness of breath, chest tightness, cough, and mucus production. Studies show that when you stop smoking cannabis these symptoms are relieved.