Neuron-specific enolase 20.1ng/ml is mildly elevated. Neuron-specific enolase is a tumor marker, normally the normal reference range should be less than 16.3ng/ml, the current test result is 20.1ng/ml, which is slightly higher than the normal value. Elevated neuron-specific enolase is likely to be caused by certain diseases, most commonly seen in some tumor diseases, such as neuroblastoma, small cell lung cancer, neuroendocrine tumors, etc., and may also be caused by craniocerebral injury, encephalitis, acute cerebral infarction and so on. However, one examination is not able to determine whether it is caused by the disease or not, and it needs dynamic testing and review, combined with other examinations to confirm the diagnosis. It is recommended to actively cooperate with the doctor to do further examination, and take targeted treatment or therapy after a clear diagnosis.