Increased FDG metabolism is considered to be malignancy. When there is increased FDG metabolism, it is necessary to test for malignancy and other problems, such as inflammatory infections or inflammatory pseudotumors, cannot be completely ruled out. It may also be caused by tuberculosis problem, or may be caused by abnormal glucose metabolism in the heart, lung and brain. It is not possible to judge the presence of cancer by increased FDG metabolism, and other tests are needed to make a clear diagnosis, and histopathological biopsy or malignant tumor screening can be performed. Fdg test is mainly for malignant tumor problems with unknown primary lesions, and the relative test value is more accurate and can be used clinically as a basis for cancer diagnosis. Increased metabolism alone needs to be combined with imaging and other pathological examinations to confirm whether cancer is present.