High neuron-specific enolase may be the result of conditions such as nerve cell damage or small cell lung cancer. Neuron-specific enolase is an enzyme specific to neurons and neuroendocrine cells, and can be used as a sensitive indicator for evaluating the severity of nerve cell injury as well as determining prognosis. Neuron-specific enolase has the highest activity in cells of brain tissue and is an enzyme involved in glucose metabolism mainly present in nerve tissue. Elevation of neuron-specific enolase is often indicative of various types of neurological injuries, such as cerebral hemorrhage, cerebral infarction, cerebral hypoxia, and so on. High neuron-specific enolase is also seen in various tumor diseases, especially in the diagnosis of small cell lung cancer, and is a specific tumor marker. Common tumor diseases that cause high neuron-specific enolase include pheochromocytoma, insulin cell tumor, medullary carcinoma of the thyroid, and so on. If the enzyme is high in clinical examination, it is necessary to go to the relevant department for screening immediately. For example, patients with small cell lung cancer need to undergo chest CT and early screening for lung cancer, and should be actively treated after clear diagnosis.