How your lungs work

What else do the lungs do?

The lungs are exposed to the air so they also play an important protective role in your body, linked to your immune system.

Each breath of air doesn’t only carry oxygen, it also carries germs and other foreign bodies such as pollutants. As a result, your lungs are also designed to prevent unwanted materials from getting into your body.

Mucus is produced in the walls of the small airways to help keep your lungs clean and well lubricated. It is moved by tiny hairs called cilia that line your airways. They move back and forth sweeping a thin layer of mucus out of your lungs and into your throat. Unwanted materials stick to the mucus. When it reaches the throat, it’s usually swallowed without you realising.

If your mucus builds up or if you have an inflammation, coughing can help to clear it from the airways.

So the delicate structure of your lungs is beautifully adapted to breathe and, at the same time, helps protect your body from harm.

But your lungs can be damaged if you breathe in cigarette smoke, polluted air or dusts and fumes in your workplace over a sustained period of time. If your airways get damaged, you can get breathless. Often it’s hard to protect yourself from environmental risks such as air pollution. But you can help protect your lungs by quitting smoking, improving the air quality in your home and doing what you can to reduce your exposure to air pollution.

If you have a lung condition there is plenty of support and advice for you on how to keep active. Attending a pulmonary rehabilitation  programme is another way to help improve your fitness and improve how you use the oxygen that is delivered to your muscles.

Download our how your lungs work PDF (488KB)

Last medically reviewed: February 2018. Due for review: February 2021

This information uses the best available medical evidence and was produced with the support of people living with lung conditions. Find out how we produce our information. If you’d like to see our references get in touch.