Lung cancer is the most occurring cancer and causing death worldwide. The major cause of cancer formation in the lungs is smoking. Passive exposure to cigarette smoke also contributes to cancer. Lung cancer may be of two types; small cell carcinoma and nonsmall cell carcinoma. According to the severity of disease, it classified into four stages. It mostly not diagnosed early as it manifested respiratory problems like symptoms like shortness of breath, coughing, and fever. But if diagnosed properly it can treat with chemotherapy, radiotherapy or surgical excision.