Cerebrospinal fluid leukocytes 30×10^6/L, other indicators are normal usually suggest that there may be encephalitis, cerebral edema, etc., should be combined with other tests to clarify the diagnosis. General cerebrospinal fluid examination includes intracranial pressure measurement; color and clarity of cerebrospinal fluid; cell count of cerebrospinal fluid and classification; protein content; sugar and chloride levels, etc. The normal range for cerebrospinal fluid white blood cell count is (0-5) x 10^6/L in adults . A cerebrospinal fluid white blood cell count of 30 x 10^6/L is mildly elevated, and all other indicators are normal usually suggesting possible encephalitis. If the mononuclear cell classification is high, viral encephalitis is more likely, and if the multinucleated cell classification is high, bacterial encephalitis cannot be excluded. However, the diagnosis of the disease needs to be accompanied by clinical symptoms and other auxiliary tests, and the cerebrospinal fluid test alone cannot determine what kind of disease it is, and the clinician needs to make specific judgment according to the situation.