Lung nodules with unclear borders generally refer to nodular lesions in the lungs with blurred borders, and are considered to be pulmonary imaging manifestations caused by lung infections, tuberculosis, or lung cancer. Inflammatory lesions caused by bacterial or fungal infections in the lungs often show indistinct lung nodules on CT imaging, and most nodules disappear after anti-infective treatment. Mycobacterium tuberculosis invades the lungs and easily forms tuberculosis balls, which often manifests as poorly defined lung nodules on imaging, and usually requires standardized anti-tuberculosis treatment to make the lung nodules disappear. In some lung cancer patients, some lung nodules with unclear boundaries can be seen on CT and other imaging examinations, and they need to take surgical treatment, radiotherapy, targeted therapy and other methods to control lung cancer, and some of them may be cured and the nodules will disappear.