Health Effects of Smoking: What It Does to Your Body

Smoking harms almost every part of the body. Health Canada links it to more than two dozen diseases and conditions, including cancer, heart disease and lung disease, and says it causes 85% of all new lung cancer cases in Canada. This section collects our guides on those harms, on nicotine, and on how much of the damage eases after you quit.

The short version

Tobacco smoke is a mixture of more than 7000 chemicals, and over 70 of them are known to cause cancer, according to Health Canada. The risks fall into a few groups: the heart and blood vessels, certain cancers, the lungs and airways, and premature death. Smoking also causes cardiovascular disease, including heart attacks, angina and strokes.

There is a hopeful side in the same Health Canada pages. Most of these risks start to reverse once you quit, and some benefits begin within hours.

Start here

Pick the question that sounds most like yours.

“What is smoking doing to my body?” Begin with cigarette side effects, which covers short-term and long-term harm to the heart, lungs, skin and teeth. For the chest specifically, see smoker’s lungs compared with healthy lungs and COPD stages and smoking.

“Is my cough a problem?” Read smoker’s cough: causes and when to see a doctor. A cough that lingers is worth a conversation with a clinician.

“What about a specific disease?” We have separate guides on smoking and cancer, heart disease, stroke and diabetes. For the legs, see smoking and blocked leg arteries. Others cover eye and oral health, teeth, skin and appearance, and fertility, pregnancy and the baby.

“I have surgery coming up.” When to quit smoking before surgery covers timing, healing and vaping.

“How long does nicotine stay in the body?” See how long nicotine stays in your system.

“How many people vape?” Vaping statistics in Canada shows rates by age, sex and province.

“What are the numbers?” Smoking statistics in Canada shows who smokes, by province and age. For young people, see youth smoking and vaping rates, and for the financial side, the economic cost of tobacco in Canada.

“What happens if I stop?” What happens when you quit smoking lays out the timeline, and how lungs recover after quitting goes deeper on the chest. When you are ready, the quit smoking hub lists free help and medications.

Tools

Two calculators sit in this section. The pack-year calculator turns your smoking history into the figure doctors use. The lung screening eligibility checker helps you see whether you may qualify to ask about screening.

Other people’s smoke

Harm is not limited to the person holding the cigarette. Our guide to the health effects of second-hand smoke covers that. Vapour has its own page: e-cigarette risks and benefits.

What we could not confirm

Risk figures describe groups of people, not individuals, and your own risk depends on how long and how much you have smoked, your age and other health factors. We report what Health Canada and Statistics Canada publish and do not estimate personal risk. Health information here is general. It is not medical advice, and anyone with symptoms should speak to a doctor, nurse practitioner or pharmacist, or call 811 where it is available.