CSF glucose test

CSF Glucose Test

The CSF glucose test or cerebrospinal fluid (CSF) glucose test is a medical test that measures the amount of glucose in the fluid that surrounds the brain and spinal cord. It is a noninvasive test that can provide important information about how the body is functioning and help diagnose a variety of conditions.

What is the Purpose of a CSF Glucose Test?

A CSF glucose test is used to detect and diagnose a variety of conditions related to the central nervous system (CNS). It is used to help diagnose meningitis, a bacterial infection of the membranes that line the brain and spinal cord.It can also be used to measure the degree of hypoglycemia (low blood sugar), which can be caused by an insulin overdose or other medical condition.


A CSF glucose test may require no special preparation. Depending on the age of the patient, they may need to fast, or their caretaker may be requested to withhold food and fluids prior to the test. For infants, this may include withholding breast milk or formula for 2 to 4 hours prior to the test.


A CSF glucose test can be performed in a doctor's office, a clinic, or a hospital. The procedure takes about 30 minutes.

  • A thin needle is inserted between the vertebrae in the lower back, and is used to draw a small sample of cerebrospinal fluid.
  • The collected sample is then sent to a laboratory, where it is tested for glucose levels.
  • The results are usually ready within 24 hours.

Types of CSF Glucose Tests

There are two types of CSF glucose tests:

  • An immunoassay test, which is typically used to diagnose meningitis.
  • A spectrophotometric test, which is used to measure the degree of hypoglycemia.

Risks of a CSF Glucose Test

The risks of a CSF glucose test are minimal. Common side effects include a mild headache or dizziness. In rare cases, more serious complications may occur, such as bleeding or infection.

Why is a CSF Glucose Test Done?

A CSF glucose test is done to check for a variety of conditions related to the central nervous system. It may be used to diagnose meningitis or hypoglycemia.

When is a CSF Glucose Test Needed?

A CSF glucose test may be recommended if a doctor suspects a patient has a CNS infection or other condition that affects the amount of glucose in the CSF. It may also be ordered if a patient has symptoms such as headache, confusion, dizziness, or seizures.