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Healtheuniversity > English > Cardiac College > Treat Heart Disease > Risk Factors > Smoking, Tobacco, Marijuana, and Alcohol

Smoking, Tobacco, Marijuana, and Alcohol

Smoking and Tobacco

Smoking (a cigarette, cigar, or pipe), vaping (e-cigarette), and chewing tobacco increase the chance that you will have a stroke, develop heart disease and peripheral vascular disease (a disease of your blood vessels), or worsen these conditions if you have them. It is known to cause several types of cancer and lung disorders.

Carbon monoxide and many of the other harmful chemicals in cigarette smoke cause many health problems. Smoking can:

  • Damage your arteries, causing a buildup of plaque on your artery wall, and reduced blood flow to your heart
  • Increase the chance that you will develop blood clots
  • Reduce the amount of oxygen in your blood
  • Increase your blood pressure and make your heart work harder. These effects can lead to a heart attack or stroke. Learn more about how high blood pressure affects your health »

Nicotine is a highly addictive substance found in tobacco products. Using products that contain nicotine can lead you to keep using these products and damage your health.

Second-hand smoke is smoke that you breathe when you are near:

  • The tip of a burning cigarette, cigar, or pipe
  • A person who is breathing out the smoke from a cigarette, cigar, or pipe

Second-hand smoke contains the same harmful chemicals that are found in a cigarette. Second-hand smoke increases your risk for health problems. There is no safe distance from a burning cigarette.

Visit the following websites to learn more about smoking and tobacco and to find support to quit:


Marijuana (also called cannabis, weed, and pot) refers to parts of or products from the cannabis plant that contain high amounts of tetrahydrocannabinol (THC). THC increases the chance that you will develop heart, brain, and vascular diseases, or worsen these conditions if you have them. THC also increases your heart rate and increases the risk of arrhythmias (heart rhythm problems). Recent research suggests that smoking marijuana increases your risk of stroke and heart attack.

To learn more, watch this video on Medical (and Recreational) Marijuana and the Heart (opens in new window) »


Drinking too much alcohol can lead to many health problems, including heart failure, high blood pressure, heart attack, stroke, and cancer. If you do not drink, do not start. If you drink, consider drinking less or quitting to improve your health.

Previous research suggested that drinking moderate levels of alcohol could protect against heart disease. However, more recent research shows that any small benefit to your health is offset by the fact that alcohol increases your risk of developing cancer.

Canada’s Guidance on Alcohol and Health published in 2023 states that there is no safe level of alcohol intake. The risk to your health increases as you increase the number of drinks you have each week:

  • 0 drinks each week — Not drinking has benefits, such as better health, and better sleep.
  • 2 standard drinks or less each week — You are likely to avoid alcohol-related consequences for yourself or others at this level.
  • 3 to 6 standard drinks each week — Your risk of developing several types of cancer, including breast and colon cancer, increases at this level.
  • 7 standard drinks or more each week — Your risk of heart disease or stroke increases significantly at this level.
  • Each additional standard drink radically increases the risk of alcohol-related consequences.

Find resources below to help you quit drinking alcohol or to drink less.

Paradis, C., Butt, P., Shield, K., Poole, N., Wells, S., Naimi, T., Sherk, A., & the Low-Risk Alcohol Drinking Guidelines Scientific Expert Panels. (2023). Canada’s Guidance on Alcohol and Health: Final Report. Ottawa, Ont.: Canadian Centre on Substance Use and Addiction. Accessed February 2024:


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