The list of health risks associated with smoking and tobacco use is a long one, and at the top of the list is premature death and reduced quality of life. Nearly half of all smokers who do not quit will die because of smoking. And they will die an average of 8 years earlier than someone like them who does not smoke.

On the other hand, quitting smoking has many benefits. Within hours of quitting, many harmful effects that smoking has had on the body begin to reverse, and life expectancy gradually improves. Read "Benefits of quitting smoking" to learn more.

If you smoke - whether it's cigarettes, cigars, or a pipe - you are at increased risk of the following conditions:

Heart, blood vessel, and circulation problems

Smoking doesn't just harm your lungs - it also puts your heart at risk.

Smoking steals your oxygen. With each inhalation of cigarette smoke, you breathe in carbon monoxide and other gases. These toxins take the place of oxygen in your body. And without this oxygen, your heart muscles are starved of the nutrients they need to function. To try to make up for the lost oxygen, your heart is forced to beat faster and work harder. Nicotine and carbon monoxide from cigarette smoke can cause the walls of your blood vessels, veins, and arteries to become blocked and hardened by deposits of fat.


A stroke occurs when the brain does not receive enough blood flow. Without blood, the brain does not get the necessary nutrients and oxygen. This can lead to permanent damage, such as full paralysis, partial paralysis, loss of speech, or loss of sight. If you smoke, you are 2 to 4 times as likely to have a stroke as someone who doesn't smoke. The risk increases with the number of cigarettes smoked per day. If you smoke more than 25 cigarettes per day, you have the highest risk of a stroke.

Smoking is responsible for over one-third of stroke-related deaths in Canada.


One of the best things you can do to reduce your risk of cancer is to quit smoking. Many of the toxic chemicals in tobacco smoke are known or probable human carcinogens (cancer-causing agents) and can cause the following types of cancer:

  • bladder
  • bowel
  • cervix
  • colon and rectum
  • esophagus
  • kidney
  • larynx (voice box)
  • leukemia
  • lung
  • mouth
  • pancreas
  • throat

Of all the cases of lung cancer in Canada, about 85% are related to smoking. If you smoke, your risk of dying from lung cancer can be up to 25 times as high as it would be if you didn't smoke. And it's not just smokers who are killed by lung cancer. Second-hand smoke is the second leading cause of lung cancer in Canada.

Lung conditions

Cigarette smoking is the major cause of chronic obstructive pulmonary disease (COPD), which includes chronic bronchitis and emphysema. Smoking does this by irritating your breathing tubes and damaging them.

Chronic bronchitis occurs when the airways in your lungs have become narrow and partly clogged with mucus. Emphysema occurs when some of the air sacs deep in your lungs have been damaged.

Smoking also increases your risk of getting the flu and colds.

Oral problems

Tobacco exposure, whether in the form of chewing tobacco or smoking cigarettes, pipes, or cigars, greatly increases your risk of getting mouth cancer and other mouth diseases. In fact, people who smoke cigarettes are about 5 to 10 times as likely to get mouth (oral) cancer as are non-smokers. The most common places that mouth cancer occurs include the:

  • floor of the mouth
  • gums
  • tongue

Another disease that can affect the gums besides cancer is periodontal (gum) disease. This disease is known in its early stages as gingivitis. Gingivitis is a condition where the gums swell, redden, and bleed because of a buildup of bacteria. Although non-smokers can also develop gingivitis because of poor oral hygiene, the toxic chemicals from tobacco increase your risk of developing this gum disease.

Full-blown periodontal disease is a more serious infection that leads to pockets forming around the teeth. As these pockets become infected, the body tries to kill off the bacteria, but instead it causes damage to the gums and bone holding the teeth in place. This can eventually lead to tooth loss. If you quit smoking and maintain good oral hygiene, you can greatly reduce your chances of gum disease.

Erectile dysfunction

Erectile dysfunction, a condition that prevents a man from being able to get or keep an erection, is twice as likely to affect those who smoke. Even men who are exposed to second-hand smoke have a greater risk of experiencing erectile dysfunction.

Millions of men are affected by erectile dysfunction, but one way to significantly reduce your risk is to quit smoking.

Other conditions

Smokers are also at increased risk of osteoporosis, sleep problems, cataracts, and thyroid disease. Their skin tends to wrinkle more and show more signs of premature aging. Smokers may also experience decreased senses of taste and smell.

Women who smoke put themselves in danger of developing cervical cancer, menstrual problems, infertility, and miscarriage. And male smokers may face infertility due to problems with sperm.

Those who use smokeless tobacco are also at risk because smokeless tobacco contains many of the same chemicals as cigarettes, cigars, and pipes. Smokeless tobacco (chewing tobacco, snuff) can cause oral cancer and throat cancer, tooth discolouration, receding gums, and tooth loss.

The good news is that you can greatly reduce your risk of smoking-related health problems by quitting smoking. Find more detailed information in "Benefits of quitting smoking."

Written and reviewed by the MediResource Clinical Team