Proliferative foci are usually found in the lungs mainly due to chronic tuberculosis infection and require prompt medical treatment. Tuberculosis generally after standardized treatment or no treatment of tuberculosis patients, easy to appear in the lung exudate, nodules, calcification, proliferation or fibrosis and other changes, of which proliferative foci is between the exudate and calcification of the relatively stable state of the foci, which indicates that the patient may be in the presence of tuberculosis in the past. Proliferative foci are mostly benign lesions caused by tuberculosis, so once the proliferative foci become active, it is necessary to be alert to whether it is a recurrence of tuberculosis. For example, those who suffer from diabetes mellitus and have unstable glycemic control are very prone to recurrence of the proliferative foci of the lungs, which may lead to recurrence of tuberculosis infection.