2 lung cancer warning signs you should never ignore, including unusual phlegm

Lung cancer is the second most common cancer after breast cancer, and kills more people than any other cancer.

Tobacco smoking is the main cause of lung cancer and about 80-90% of lung cancers can be attributed to it.

Cancer that begins in the lungs is called primary lung cancer, while cancer that spreads to the lungs from another place in the body is known as secondary lung cancer