Lung cancer is the leading cause of cancer death for both men and women. There are two major types of lung cancer –small cell lung cancer and non-small cell lung cancer. If a lung cancer has characteristics of both types, it's called a mixed small cell/large cell cancer, though this isn't common.
A major risk factor for lung cancer is smoking, and exposure to secondhand smoke. Being exposed to radon, asbestos, radioactive dust or arsenic can also increase your chances of getting lung cancer.
Lung cancer may spread within your chest and then to other parts of your body, causing symptoms in unexpected places. For example, if it spreads to your spine or bones it may cause pain in your back or other bones, or weakness in your arms or legs. If it spreads to your brain, it may cause seizures, headaches, or vision changes.