Health Effects of Smoking

Smoking is the leading cause of preventable disease and death. It can harm almost every part of your body and lower your overall health. Knowing the risks can help you make safer choices.

What health problems can smoking cause?

Smoking can lead to many serious health problems, including:

• Heart disease: Smoking increases the chance of heart attacks, blood clots, and stroke.

• Cancer: About 85-90 per cent of lung cancer cases are caused by smoking. It also raises the risk of cancers in the mouth, throat, bladder, stomach, and more.

• Breathing problems: Smoking damages your lungs, making it harder to breathe and increasing the risk of diseases like asthma, bronchitis, and chronic obstructive pulmonary disease (COPD).

Half of all long-term users will die of a tobacco-related illness. For more information, check out Health Canada’s page on smoking and health risks.

How does smoking affect pregnancy and babies?

Smoking during pregnancy can lead to harmful effects such as:

• Early birth delivery

• Stillbirth - death of the baby before birth

• Low birth weight

• Ectopic pregnancy - baby is growing outside of the womb

• Orofacial clefts - an opening or split of the upper lip in babies

What is second-hand and third-hand smoke and how can it affect you?

Second-hand smoke: This is the smoke you breathe in from someone else's cigarette, vape, or other tobacco product. Even if you’re not the one smoking, being around second-hand smoke can harm your health. It’s especially dangerous for children, seniors, and people with breathing problems.

Third-hand smoke: This is the leftover smoke and chemicals that settle on surfaces like clothes, furniture, walls, and even in carpets. These toxins can stay around long after someone has smoked and can be harmful, especially for young children and pets who might touch or breathe them in.

Learn more about second-hand and third-hand smoke from the Canadian Cancer Society.

Why is smoking so hard to quit?

Smoking is addictive because of a chemical called nicotine. Nicotine affects the brain by creating feelings of pleasure and relaxation, which can make you want to keep smoking. Over time, your body and brain get used to having nicotine, so you feel the need to smoke more to get the same effects. This is called dependence.

When you try to quit, you might feel withdrawal symptoms like cravings, irritability, and trouble concentrating, which makes it harder to stop. This is why many people find it challenging to quit smoking, even when they know it’s harmful to their health. 

What are the benefits of quitting?

Within 8 hours: The carbon monoxide level drops in your body. (Carbon monoxide is a toxic gas that enters your blood when you smoke) The oxygen level in your blood increases to normal.

Within 48 hours: Your chances of having a heart attack go down. Your sense of smell and taste get better.

Within 72 hours: Breathing is easier.

Within 2 weeks to 3 months: Blood circulation improves. Your lungs will work up to 30% better.

Within 6 months: Coughing, sinus congestion, tiredness and shortness of breath improve.

Within 1 year: Your risk of suffering a smoking-related heart attack is cut in half.

Within 10 years: Your risk of dying from lung cancer is cut in half.

Within 15 years: The risk of dying from a heart attack is equal to a person who never smoked.

What should I do next?

If you’re thinking about quitting smoking, we’re here to help. Explore our Quit Smoking page for information about programs and services available to you.