A sudden blackening is cancer.

The sudden blackening of the face may be due to a certain acute condition in the body, which may be a tumor, but I think we should first rule out the possibility of some cardiovascular and cerebrovascular diseases causing insufficient blood supply to the head and face. Tumor is not the only factor in some facial changes. Of course, we also need to combine some other manifestations of the patient, such as his blood pressure changes, his heart rate, to comprehensively determine that the face is only a factor, tumor alone will rarely cause changes in the face, but advanced tumor, may cause adverse effects on the overall body condition, face may occur some abnormal changes, but there is no direct causal relationship between the two.