Symptoms and Causes of Lung Cancer

Lung cancer is a type of cancer that begins in the lungs. Your lungs are two spongy organs in your chest that take in oxygen when you inhale and release carbon dioxide when you exhale.

Lung cancer is the leading cause of cancer deaths worldwide.

People who smoke have the greatest risk of lung cancer, though lung cancer can also occur in people who have never smoked. The risk of lung cancer increases with the length of time and number of cigarettes you’ve smoked. If you quit smoking, even after smoking for many years, you can significantly reduce your chances of developing lung cancer.

Symptoms

Lung cancer typically doesn’t cause signs and symptoms in its earliest stages. Signs and symptoms of lung cancer typically occur when the disease is advanced.

Signs and symptoms of lung cancer may include:

• A new cough that doesn’t go away
• Coughing up blood, even a small amount
• Shortness of breath
• Chest pain
• Hoarseness
• Losing weight without trying
• Bone pain
• Headache

What causes lung cancer?

Anyone can get lung cancer, but 90 percent of lung cancer cases are the result of smoking.

From the moment you inhale smoke into your lungs, it starts damaging your lung tissue. The lungs can repair the damage, but continued exposure to smoke makes it increasingly difficult for the lungs to keep up the repair.

Once cells are damaged, they begin to behave abnormally, increasing the likelihood of developing lung cancer. Small-cell lung cancer is almost always associated with heavy smoking. When you stop smoking, you lower your risk of lung cancer over time.

Exposure to radon, a naturally existing radioactive gas, is the second leading cause, according to the American Lung Association.

Radon enters buildings through small cracks in the foundation. Smokers who are also exposed to radon have a very high risk of lung cancer.

Breathing in other hazardous substances, especially over a long period of time, can also cause lung cancer. A type of lung cancer called mesothelioma is almost always caused by exposure to asbestos.

Other substances that can cause lung cancer are:

• arsenic
• cadmium
• chromium
• nickel
• some petroleum products
• uranium

Inherited genetic mutations may make you more likely to develop lung cancer, especially if you smoke or are exposed to other carcinogens.

Sometimes, there’s no obvious cause for lung cancer.