Lung cancer is like other types of cancers that results from the abnormality in the cell of the body. Under normal conditions, the human body maintains the system of checking and balancing the cell growth to enable cells divide further to form new cells when cells are needed. Disrupt in this system of cell growth lead to an uncontrolled division that forms the mass of cells called as tumor. Some of the symptoms and signs of lung cancer are cough that gets worse, hoarseness, loss of appetite, chest pain at the time of deep breathing, laughing and coughing, weight loss, feeling tired, coughing up blood, shortness of breath and infections such as pneumonia and bronchitis that keep coming back again and again. If this cancer spreads to other organs it can lead to change in nervous system, bone pain and yellowing of eyes and skin.
Smoking cigarettes is the biggest cause or factor of lung cancer. This can cause cases above 8 out of the 10 cases that include a small proportion lead by the exposure to passive smoking. Risk of this cancer gets increased as per the count of cigarettes smoked by the person over certain period of time. Passive smoking is inhaling the tobacco smoke released from smokers who share their living quarters. Some of the other risk factors included in lung cancer are exposure to the radon gas, air pollution, exposure to certain type of chemicals; previous lung disease faced by people, lowered immunity, past cancer treatment, family history of this problem and previous smoking that relate the cancer. Some of the chemical substances that lead to lung cancer are asbestos, diesel exhaust, some forms of chromium and silica and arsenic. People who have workplaces where these substances are involved will have increased chances of getting affected by lung cancer.