Lung cancer patients do not only have cancer pain at night, cancer pain can also appear during daytime, but the frequency of attack and the degree of pain caused by lung cancer disease are more obvious at night. Lung cancer patients seldom have pain in the early stage, but as the disease develops into middle and late stage, due to the dissemination of lung cancer lesions in the body, pain symptoms in several parts of the body will appear, for example, chest pain caused by invasion of lung cancer to the pleura or ribs, abdominal pain caused by invasion of liver, lumbago caused by invasion of lumbar vertebrae, and so on. Cancer pain is usually characterized by chronic, complex, gradual and explosive, which is difficult to be effectively controlled by general painkillers, and the degree is usually more serious. This kind of pain can occur at any time, and it is usually aggravated after activities, or the attack is frequent at night, or the degree of pain at night is more serious than that in the daytime.