Skip navigation |

Understanding Lung Cancer

How do my lungs work?
Everyone has two lungs; each lung is divided into smaller sections called lobes - three on the right and two on the left. The inside of your lungs are like a large sponge. Every part of your body needs oxygen to function. When you breathe in, fresh air brings new oxygen into your body and when you breathe out, used breath is removed. Each time you breathe in, the air flows into your nose or mouth down through your throat and into your windpipe (trachea). The trachea divides into two smaller passages called the left and right bronchi.

Like branches, the bronchi divide again and again, branching into much smaller tubes (bronchioles), which take the air to millions of tiny air sacs called alveoli, and into the blood. This oxygenated blood is then carried from your lungs to the heart, which pumps the blood throughout the body.

Diagram of lungs

What is lung cancer?
Lung cancer is a term used to describe a growth of abnormal cells inside the lung - these cells reproduce at a much quicker rate than normal cells. The abnormal cells grow to form a growth, a lump that is described by doctors as a tumour. If the abnormal cells first start growing in the lung, it is called primary lung cancer. If the abnormal lung cells break off and travel, they may start to grow in other areas of the body, for example bones. This new growth is called a secondary cancer or metastasis.

What causes lung cancer?
Although around 10-15% of people who are diagnosed with lung cancer have never smoked, in the vast majority of cases tobacco smoking is the main cause of someone's lung cancer. There are other risk factors that can increase the lung cancer risk, but this risk is far less than with smoking:

  • Passive smoking.
  • Exposure to asbestos, radon gas and chemicals.
  • Poor diet and lack of exercise.

Is there a cure for lung cancer?
Yes, it is possible to be cured of lung cancer, but it is important to realise that there are many different types of lung cancer. Your treatment and chance of cure will depend on the following:

  • Where in the lung the tumour is growing.
  • The kind or type of abnormality making the cancer cells.
  • The size of the cancer and how long it has been growing.
  • How fast the cancer is growing and if it has spread to other parts of your body.
  • Physical and emotional fitness.

All of the above will influence your treatment. Lung cancer treatments are developing all the time. People may think that surgery is the only effective treatment for lung cancer. This is not always true. Your doctors will consider carefully the best treatment for you. You and your family should understand and feel comfortable with the treatment you are having and why. Do ask about the treatment that has been suggested for you and why it is the best option.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we'll assume that you are happy to receive all cookies on the The Roy Castle Lung Cancer Foundation website. To find out more about the cookies, see our privacy policy.