How much brain fluid is normal?
On One Hand: Normal Fluid LevelThe brain shares fluid–called cerebrospinal fluid (CSF)–with the spine. CSF flows freely between the two, and the normal total volume in adults is about 140 ml. The adult human body produces 600 to 700 ml of CSF per day, and it is reabsorbed through the blood stream.On the Other: High Fluid LevelsExcessive CSF levels cause pressure on the brain, a condition known as hydrocephalus. This may be caused by genetic factors, developmental abnormalities, tumors, trauma or diseases, such as meningitis. Hydrocephalus can be treated by the surgical insertion of a shunt to drain the fluid and reduce pressure on the brain.Bottom LineThe normal volume of CSF in an adult is 140 ml, but because completely draining a patient’s fluid for measurement is impractical, doctors rely on CSF pressure readings to determine if the volume is normal. Normal pressure is 70 to 180 ml.
