【正文】 ? cerebral edema, cerebral hemorrhage, brain tumors ? Extracranial： hypertension, congestive heart failure ?Decrease:CSF circulation obstruction, loss or impairment in secretion Color changes Color of CSF Conditions or causes Clear, colorless normal Milky With WBC increase Pink to yellow With blood Yellow Hyperbilirubinemia Protein≥Green Purulent CSF Brown to Black Meningeal melanoma Transparency ?Normal :Clear, colorless ?Clear or Cloudy： ? Viral Meningitis、 Epidemic Encephalitis B or Syphilis in CNS ?Ground glass opacity： Tuberculous Meningitis ?Milky turbid： Purulent Meningitis Clots and film ?Normal: No clots or film in 24 hours ?Purulent Meningitis :clots observed in 12 hours ?Tuberculous Meningitis :thin film cover after 12—24 hours ?Suba