Lung cancer: what is it?
What are the lungs?
Lungs are for breathing. You have 2 of them, one on each side of your heart. When you breathe in they stretch and get bigger; when you breathe out they get smaller. But they're not hollow—they're full of little passages and holes for the air. They're more like sponges than bags.
When you breathe in, air goes into your windpipe, a big tube that runs down your neck from the back of your throat. At the top of your chest the windpipe splits into two smaller tubes called your left and right bronchus (the plural is bronchi), which lead to your 2 lungs. Once there, the bronchi divide into thousands of little tubes, which go all through the lungs and end in millions of tiny air pockets.
This is where oxygen from the air you breathe goes into your blood, and carbon dioxide, used air, comes out of your blood and into your lungs to be breathed out. You can't live long without oxygen. Your lungs are pretty important.
What is lung cancer?
Lung cancer happens when some of the cells in your lungs start to grow out of control. It usually begins in the lining of the airways—the tubes and passages that carry air into and through your lungs.
It's the most common cancer in the world—and is almost impossible to cure.
There are lots of different types of lung cancer, but most of them belong to one of 2 main groups—small cell carcinoma (sometimes called oat cell carcinoma) and non-small cell carcinoma. The 2 types look different under a microscope, and because they grow and spread in different ways, they're treated differently.
Cancers beginning in other parts of the body can spread to the lungs, but this isn't lung cancer. These cancers are called lung secondaries, or metastases.
For further information and advice, call the Cancer Helpline on 13 11 20
Last Reviewed: 03 January 2002
