Cerebrospinal Fluid (CSF) Cell Count (with Differential)

Why This Test Is Done

Doctors may order this test if you have symptoms like severe headaches, neck stiffness, fever, confusion, or neurological problems. It’s often done when there’s suspicion of conditions like meningitis, brain tumors, multiple sclerosis, or other brain-related illnesses. A lumbar puncture (spinal tap) is typically performed to collect the CSF for testing.

What to Expect Before the Test

You’ll likely be asked to fast for a few hours before the test, though this isn’t always required. Bring your medical records or any medications you’re taking, as these can affect results. You may also need to wear loose clothing for the procedure.

What Happens During the Test

A healthcare provider will insert a needle into your lower back to collect a small amount of CSF. You may feel pressure or a slight sting, but it’s usually over quickly. The procedure takes about 15–30 minutes, and you’ll be monitored closely for any complications.

What the Results Mean

High cell counts (especially white blood cells) may indicate infections (like meningitis), inflammation, or other neurological conditions. Low cell counts might suggest bleeding, certain brain diseases, or normal findings. Your doctor will interpret results in the context of your symptoms and medical history.