The high incidence of lung cancer is usually above 45 years of age, and there have been cases before at 8 years of age, but the incidence of this condition is extremely low. Therefore, it is recommended that people over 45 years of age should have routine lung checkups every year, even if they do not smoke. Because of the relatively heavy air pollution, hazy weather, and the frequent presence of secondhand smoke, it is very necessary for people over 45 years of age to go to the hospital for routine annual checkups, including pulmonary checkups. Before the age of 45, you may not do a lung CT examination, but a chest X-ray examination is more appropriate. Therefore, it is recommended that all people over 45 years of age, regardless of whether they smoke or not, should have regular annual checkups, including lung CT exams, to reduce the occurrence of lung cancer.