CSF is collected in 4 vials so departments will have enough for testing. This CSF appears clear, colorless and normal.By James Heilman, MD - Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=6992139
This image shows the ventricles where CSF circulates.By OpenStax - https://cnx.org/contents/[email protected]:fEI3C8Ot@10/Preface, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=30147960
CSF that is yellowish in color is xanthrochromic. This is usually the result of a traumatic spinal tap in which blood leaks into the subarachnoid space and is detected several hours later in the CSF. This may also be the result of subarachnoid hemorrhage, which may be due to trauma, stroke, cerebral aneurysm that has ruptured, cancer, or other condition. Spinal tap is indicated if patients experience a thunder-like headache, nausea, vomiting, light sensitivity, stiff neck, dizziness, seizures or convulsions, confusion, loss of consciousness, coma, and/or signs of increased intracranial pressure.
Bloody CSF
Bloody CSF is of concern because though it may be caused by a traumatic spinal tap, it may be linked to the presence of bacteria, meningitis or fungi causing meningitis, or something just as serious, including a blood clot, stroke, ruptured aneurysm, intracranial hemorrhage, or cancer.
Cloudy CSF
Cloudy CSF is a sign of inflammation and possible infection, which may be viral, bacterial, fungal, and rarely, caused by a parasite.
By Jensflorian - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=11947217
In the image above, there are numerous neutrophils, indicating inflammation, but there are no signs of bacteria, so this indicates that the inflammation is due to another cause other than bacteria. Meningitis should be ruled out. It could be viral meningitis or cancer or lupus or sarcoidosis or a reaction to a drug or other causes.
Neutrophils and Bacteria in Bacterial Meningitis:
By Paulo Henrique Orlandi Mourao - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=29703673
In bacterial meningitis, white blood cells and bacteria, including intracellular bacteria will be seen in the CSF Gram stain.
Viral Meningoencephalitis: HIV
By Jensflorian (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons
By Jensflorian - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=41203277
In viral meningitis, typically you will see numerous lymphocytes and monocytes, but a lack of bacteria in the CSF.