The normal values listed here-called a reference range-are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
No infectious organisms (such as bacteria, fungi, or a virus) are found in the CSF sample. No tumor cells are present.
Blood in the CSF can result from bleeding (hemorrhage) in or around the spinal cord or brain, but it may also be caused by tiny blood vessel poked during the spinal tap. If a brain hemorrhage has occurred, the color of the CSF may change from red to yellow to brown over several days. Bleeding caused by the lumbar puncture itself will show more red blood cells in the first sample collected than in later samples. Cloudy CSF may mean an infection (such as meningitis or a brain abscess) is present.
High CSF pressure may occur as a result of swelling (edema) or bleeding (hemorrhage) in the brain, infection (such as meningitis), stroke, or other circulatory problems. Below-normal pressure may mean a blocked spinal canal.
Low glucose levels in the CSF are abnormal and may be caused by bacterial meningitis. Viral meningitis does not often cause low glucose levels in the CSF. Brain hemorrhage may also cause low glucose levels several days after bleeding begins. Higher-than-normal glucose levels are often caused by diabetes.
Red blood cells (RBCs) in the CSF can result from bleeding. High levels of white blood cells (WBCs) can indicate meningitis. Tumor cells and abnormal levels of white blood cells can show cancer is present.
Antibodies, bacteria, or other organisms in the CSF means that an infection (such as syphilis) or disease is present. Bacterial markers (bacterial antigens) that show up mean meningitis. Cultures or stains of the CSF may also help show the cause of meningitis or encephalitis.
Your doctor may order other special tests on the CSF fluid depending on your symptoms and past health.