Generally speaking, there are a large number of cancer cells in the lungs of patients with lung cancer, and they are constantly multiplying and growing, which not only brings great pain to patients, but also affects the mental state of their families, thus shouldering heavy mental pressure and burden. In order to prevent the disease of lung cancer, some people question the disease of lung cancer and suspect that lung cancer will spread to others, but they avoid talking about lung cancer patients. In fact, this understanding is wrong, so will lung cancer be contagious? Although lung cancer, like influenza and tuberculosis, is a respiratory disease, it is different in nature. Influenza is an upper respiratory tract inflammation caused by viral infection of respiratory tract. Due to close contact, influenza virus can infect others through breathing. Therefore, in daily life, flu patients should wear masks and don't cough at others. This is a necessary measure to avoid infection. The lung is a specific feeling of lung tissue, which is caused by tuberculosis infection. Mycobacterium tuberculosis is excreted in the sputum of patients and inhaled into the lungs by healthy people in the air. When the body's resistance drops, tuberculosis will occur. Therefore, patients with active pulmonary tuberculosis should be isolated from healthy people to avoid infecting others. So is lung cancer contagious? In fact, lung cancer is different. Although exfoliated cancer cells can often be found in the sputum of lung cancer patients, exfoliated cancer cells are easy to die in vitro and have weak vitality. Therefore, they can't float in the dust alive like mycobacterium tuberculosis and be inhaled into the lungs by healthy people to cause diseases. The cause of lung cancer is not clear, but it is definitely closely related to environmental pollution and the long-term stimulation of bronchial and lung tissues by inhaling toxic gases containing carcinogens. The experiment also shows that the transplanted cancer cells are not easy to survive, not easy to form cancer foci, and are rejected by the body. In animal experiments, it is successful to implant lung cancer cells into the lungs of the same kind of healthy animals and form cancer foci under certain conditions. However, there has never been an example of similar healthy animals suffering from lung cancer raised with animals suffering from lung cancer. The same is true of the results of clinical observation. Lung cancer patients are often treated in hospital wards, but they are never found to have tumors because they live in the same room. Many hospitals do not separate patients with lung cancer from patients with other diseases. On the other hand, long-term contact with medical staff and family members of patients with lung cancer does not increase the incidence of lung cancer. So far, no precedent of lung cancer infection has been found, as to whether lung cancer can spread. Therefore, it can be considered that lung cancer is not contagious, does not belong to infectious diseases, and will not be transmitted through breathing or diet because of frequent contact with patients. There is no need to take any isolation measures in the hospital and at home. You don't have to worry about visiting relatives and friends of patients and accompanying patients, nor do you have to worry about patients' families living with them. Of course, it is appropriate for patients to share food with others when eating at home, which is an ideal way of eating in line with sanitary habits. However, this is different from the infection of lung cancer. Therefore, to sum up, the answer to the question whether lung cancer is contagious is no, because lung cancer, a cancer disease, is a very special disease. Although it occurs in the lungs and respiratory system, it is not contagious. Because unlike tuberculosis, influenza and other viruses that enter healthy people through gas and cause diseases, lung cancer cells are easy to die and not easy to survive, so they will not spread. Therefore, the families of patients with lung cancer don't have to panic. They can wait for the patients with confidence and take careful care to help them get rid of the pain of the disease as soon as possible.