Lung cancer is a type of cancer that begins in the lungs. It is the leading cause of cancer death in both men and women. Lung cancer kills more people than any other type of cancer. Lung cancer is difficult to detect early and often has no symptoms in its early stages. There are two main types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Lung cancer is usually treated with surgery, radiation therapy, chemotherapy, or a combination of these treatments. Lung cancer can cause damage to the heart muscle, which can lead to heart failure. Lung cancer can also spread to the lining of the heart, which can lead to irregular heartbeats and cardiac arrest. Lung cancer can also compress the arteries leading to the heart, which can cause a heart attack. People who are exposed to second hand smoke are at an increased risk for developing lung cancer, even if they have never smoked cigarettes themselves.