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What color is CSF drainage?

Cerebrospinal fluid (CSF) drainage can present in different colors depending on the underlying condition causing it. In this article, we will explore the various colors CSF drainage can appear as and what they may indicate.

Normal CSF Color

Normal CSF is clear and colorless. This means that any drainage or leakage of CSF fluid should be completely transparent with no discoloration. Clear CSF indicates there is no blood, protein or other substances contaminating the CSF.

Some key points about normal clear CSF:

  • Clear CSF drainage or leakage is considered normal.
  • No red, yellow, cloudy or bloody tint to the fluid.
  • Transparent and colorless in appearance.
  • Reflects there is no contamination of the CSF with blood, protein or other substances.

As long as the CSF drainage remains clear, this is typically a good sign. However, any CSF leakage warrants medical evaluation to determine the underlying cause and treatment options.

Yellow/Xanthochromic CSF

Yellow or xanthochromic CSF indicates the presence of blood breakdown products in the CSF, specifically bilirubin. Some potential causes include:

  • Subarachnoid hemorrhage – bleeding into the space between the brain and skull.
  • Brain hemorrhage or stroke.
  • Head trauma.
  • Intracranial bleed.

In essence, the yellow color reflects previous bleeding in the brain or surrounding areas that has broken down and released bilirubin into the CSF. The more yellow the CSF appears, the higher the levels of bilirubin.

Key Points on Yellow CSF Drainage

  • Reflects previous brain bleed, head injury, hemorrhage or other trauma.
  • Caused by breakdown products of red blood cells, namely bilirubin, contaminating the CSF.
  • Color may range from pale yellow to deep yellow or xanthochromic.
  • Requires prompt evaluation to determine the cause and rule out ongoing bleeding or damage.

Red/Bloody CSF

Red or bloody CSF drainage indicates the presence of blood in the CSF, also known as a hemorrhage. Some potential causes include:

  • Head injury or trauma.
  • Brain tumor.
  • Ruptured cerebral aneurysm.
  • Brain abscess.
  • Stroke.

Red or bloody CSF reflects active or recent bleeding into the CSF pathways. The source of the bleed needs to be promptly identified.

Key Aspects of Red CSF Drainage

  • Signifies active bleeding or hemorrhage.
  • Requires urgent evaluation to determine the cause and treat appropriately.
  • Color may range from pink to bright red.
  • More concentrated or darker color reflects higher amount of bleeding.

Cloudy or Turbid CSF

Cloudy, turbid or unclear CSF indicates the presence of cellular debris, microorganisms, inflammatory proteins or other contaminants. Some potential causes include:

  • Bacterial meningitis.
  • Viral meningitis.
  • Fungal meningitis.
  • Cancer spread to CSF.
  • Neurosyphilis.

Determining if the cloudy CSF is caused by infection or another process guides the required treatment.

Key Notes on Cloudy CSF

  • Reflects some form of contamination of the CSF.
  • Can signify infection but also seen with cancer, bleeding, etc.
  • Degree of cloudiness varies from slight haze to thick opacity.
  • Requires analysis of CSF composition to determine the cause.

Green CSF

Green cerebrospinal fluid is very rare but can occur with a Pseudomonas bacterial infection. Pseudomonas aeruginos is a gram-negative bacterium that can cause a greenish-blue pigment called pyocyanin that can discolor CSF. Other potential causes include:

  • E. coli or other gram-negative infection.
  • Presence of biliverdin from spinal or cranial injuries.
  • Rare fungal infections.

Green CSF always warrants urgent investigation to identify the responsible infection and initiate treatment.

Key Aspects of Green CSF

  • Very rare finding.
  • Typically reflects a Pseudomonas or gram-negative bacterial infection.
  • Can also be seen with uncommon fungal infections.
  • Requires prompt evaluation and treatment of the underlying infection.

Brown CSF

Brown cerebrospinal fluid is uncommon but can occur with bleeding or infections. Some potential causes include:

  • Bleeding – Breakdown of red blood cells can turn CSF brown.
  • Bacterial meningitis – Infections from bacteria like Streptococcus can discolor CSF.
  • Fungal meningitis – Rare molds can contaminate CSF.
  • Meconium release – Fetal distress can cause meconium release into CSF.

Identifying the cause of brown CSF guides appropriate treatment. Bleeding requires controlling the source while infections demand antimicrobials.

Key Notes on Brown CSF

  • Uncommon finding needing prompt evaluation.
  • Can reflect hemorrhage, meningitis, fungal infections or other processes.
  • Degree of brown coloring varies widely.
  • Cause must be found quickly to initiate proper treatment.


In summary, the color of CSF drainage can provide insight into the potential cause:

CSF Color Potential Causes
Clear Normal CSF
Yellow/Xanthochromic Bleeding, trauma, stroke
Red/Bloody Hemorrhage, aneurysm, trauma
Cloudy/Turbid Infection, cancer, inflammation
Green Bacterial infection like Pseudomonas
Brown Bleeding, bacterial/fungal meningitis

While many conditions can cause CSF discoloration, prompt evaluation and identification of the cause is crucial to guide appropriate treatment. Any drainage of CSF warrants urgent medical attention, even if clear, to determine the reason for leakage and repair if needed.