Cerebrospinal Fluid (CSF) Analysis
Reviewed
Also called: Spinal Fluid Analysis, CSF Analysis
A cerebrospinal fluid (CSF) analysis tests a sample of your CSF for diseases that affect the brain and spinal cord, which make up your central nervous system.
Specimen: cerebrospinal fluid (CSf)
Urgent safety information
Some infections, such as meningitis caused by bacteria, are life-threatening emergencies. If your provider suspects you have bacterial meningitis or another serious infection, you may need to start medicine before you have a final diagnosis.
Why this test may be ordered
- Symptoms of an infection or bleeding in the brain or spinal cord
- Symptoms of an autoimmune disorder, such as multiple sclerosis (MS)
- Had a brain injury or an injury to your spinal cord
- Have cancer that may have spread to your central nervous system
- Symptoms that may be from another central nervous system condition, such as headaches
Preparation and collection
You don't need any special preparations for a CSF analysis, but you may be asked to empty your bladder (pee) and bowels (poop) before the test.
To get a sample of CSF, a provider will do a procedure called a spinal tap, also known as a lumbar puncture. A spinal tap is usually done in a hospital. When the area on your back is completely numb, your provider will insert a thin, hollow needle between two vertebrae in your lower spine. Your provider will withdraw a small amount of CSF for testing. Your provider may ask you to lie on your back for an hour or two after the procedure. This may prevent you from getting a headache afterward.
There is very little risk to having a spinal tap. You may feel a little pinch or pressure when the needle is inserted. After the test, you may feel some pain or tenderness in your back at the site where the needle was inserted. You may also have some bleeding at the site or get a headache. The headache may last for several hours or up to a week or more, but your provider may suggest treatment to help relieve the pain.
Understanding results
If a result or symptoms suggest an emergency, get emergency medical help right away.
A CSF analysis may include a variety of different tests on your sample. So, the measurements on your test results will depend on which tests were done. Your provider can explain what your results mean.
- Abnormal CSF results: In general, your CSF analysis results may show that you have an infection, an autoimmune disorder, such as multiple sclerosis (MS), or another disease or injury of the brain or spinal cord. Limitation: So, the measurements on your test results will depend on which tests were done. Next step: Your provider will likely order more tests to confirm your diagnosis.
- Signs of a serious infection such as bacterial meningitis: Some infections, such as meningitis caused by bacteria, are life-threatening emergencies. Limitation: A CSF analysis may include a variety of different tests on your sample. Next step: If your provider suspects you have bacterial meningitis or another serious infection, you may need to start medicine before you have a final diagnosis.
- The test results depend on which specific tests are included in the analysis.
- A normal result does not rule out all central nervous system conditions.
- Abnormal results are not diagnostic on their own; further testing is needed to confirm a specific condition.
What to do next
Your provider will likely order more tests to confirm your diagnosis. If your provider suspects you have bacterial meningitis or another serious infection, you may need to start medicine before you have a final diagnosis.
- What specific tests are included in my CSF analysis?
- What do my results mean for my health?
- Do I need any additional tests or follow-up?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.
U.S. National Library of Medicine: Cerebrospinal Fluid (CSF) Analysis