Smoking Lung

It will come as no surprise to most smokers that the risk of lung cancer and other lung conditions is considerably higher the longer you smoke - but it can be hard to educate yourself among the sensationalist packaging and tabloid headlines. Here, Health-on-Line provides an informative look at how the lungs work, and the effect smoking can have on them.

Healthy Lung Left Side 1 Healthy Lung Left Side 2 Healthy Lung Left Side 3 Healthy Lung Left Side 4
Healthy Lung Right Side 1 Healthy Lung Right Side 2 Healthy Lung Right Side 3 Healthy Lung Right Side 4
Left Side of a Human Lung
Right Side of a Human Lung

Air enters the lungs via the trachea


In healthy lungs 20 per cent of the air will be left in the lungs while breathing out; as we get older this rises to about 35 per cent.


The cilia are tiny hairs inside your trachea which filter the air you breathe in and remove particles of dust and pollution, catching it in mucous to be ejected from the body.


The bronchi are passageways which branch into smaller tubes to ensure air is evenly distributed across the lungs.


The alveoli are stretchy air sacs where the gas exchange takes place in the lungs, absorbing inhaled oxygen into the blood and taking carbon dioxide out to be exhaled.

Left Side of a Smokers Lung
Right Side of a Smokers Lung
Smoking Lung Left Side 1 Smoking Lung Left Side 2 Smoking Lung Left Side 3 Smoking Lung Left Side 4
Smoking Lung Right Side 1 Smoking Lung Right Side 2 Smoking Lung Right Side 3 Smoking Lung Right Side 4

Damaged and paralysed cilia cause the trachea to become blocked with mucous and dust, making air movement harder.


The amount of air left in the lungs is higher on exhaling compared to a non-smoker, making breathing much harder.


The build up of chemicals, dust and mucous means that the fatal effects of smoking are dependent on how long you have been smoking for, rather than how many cigarettes you smoke. The lungs can start to self-repair within just one month!


Smoking means that more pollution becomes trapped in the cilia, until eventually they become damaged and stop working properly. This causes a build up of mucous and increases the chance of infection as dirt is not being cleaned out of the trachea properly.


Chronic bronchitis is the most common effect of smoking to affect the bronchi, as smoke and inhaled chemicals act as an irritant which inflames the membranes of the air passages. This causes an increase in mucous production and obstruction of the airways as the bronchi attempt to heal.


Chemicals in cigarette smoke break down the thin walls of the stretchy alveoli, making it less elastic and resulting in less efficient air sacs. This means less oxygen is absorbed, making breathing more difficult and starting the development of emphysema.