This decreases the number of air spaces and blood vessels in the lungs, resulting in less oxygen to critical parts of your body.
The lungs are lined in broom-like hairs called cilia, which clean the lungs.
As a result, the amount of mucus increases and thickens.
Your lungs cannot effectively clean out this excess mucus.
Because the tar in cigarettes contain harmful chemicals, your blood stream is infected by them when you smoke.
When these poisons enter your blood: Smoking cigarettes is also quite harmful to your brain.
The more cigarettes you smoke a day, the higher your risk of cancer, so reducing the number of cigarettes you smoke a day can be a good first step. For example, a chemical, benzo(a)pyrene causes damage specifically at a part of the DNA that normally protects our cells from cancer.
Research has shown that for every 15 cigarettes smoked, there is a DNA change which could cause a cell in the body to become cancerous. A review found that people who only drank alcohol increased their risk by a third compared to non-drinkers.
But the best way to reduce your risk is to stop smoking completely. Whereas those who smoke or used to smoke, and also drank alcohol were around 3 times more likely to develop cancer than those who did neither. Lung cancer mortality in relation to age, duration of smoking, and daily cigarette consumption: results from Cancer Prevention Study II.
Alcohol may make it easier for harmful chemicals from tobacco smoke to pass through the mouth and throat into the blood stream.