Quick Answer
Spinal fluid that leaks from the nose is typically clear and colorless. However, it may take on a pink, red, yellow, or brown tinge in some situations. The most common cause of colored spinal fluid from the nose is a nosebleed that mixes with the leaking cerebral spinal fluid. Other potential causes include an infection, bleeding in the brain, or a traumatic head injury. Regardless of color, any spinal fluid leaking from the nose should be evaluated by a doctor.
What Is Cerebrospinal Fluid?
Cerebrospinal fluid (CSF) is a clear, colorless fluid that surrounds and cushions the brain and spinal cord. It serves several important functions:
- Protects the brain and spinal cord from injury
- Nourishes surrounding tissue
- Removes waste
- Maintains proper pressure and blood flow in the brain
CSF is constantly produced and absorbed to maintain a balance. It flows through four ventricles in the brain before draining into the subarachnoid space – the area between the arachnoid mater and pia mater membranes that surround the brain and spinal cord.
From here, CSF is reabsorbed into the bloodstream. An excess or reduced volume of CSF can indicate an underlying medical condition.
Normal CSF Volume and Pressure
The normal volume of CSF in adult humans is about 90-150 mL. It is constantly being produced at a rate of 20-30 mL per hour, or 500-600 mL per day.
CSF pressure is measured during a lumbar puncture (spinal tap). Normal opening pressure ranges from 5-20 cm H2O in adults and 3-19 cm H2O in children. Higher or lower pressure may signify a problem.
Causes of Spinal Fluid Leaking From the Nose
There are several possible causes for cerebral spinal fluid to leak from the nose (CSF rhinorrhea):
1. Head injury/trauma
Head injuries like a car accident, sports collision, or hard fall can fracture the thin bones separating the sinus cavities from the brain. This allows CSF to escape through the nose. Symptoms appear right after the trauma occurs.
2. Tumor or cyst
Growths in the sinus cavities, skull base, or brain may erode through surrounding bone and create an opening for CSF to drain into the nose. Symptoms often develop slowly.
3. Surgery
CSF leaks can occur as a complication of sinus, skull base, or brain surgery if an opening forms. Symptoms appear after the procedure.
4. High intracranial pressure
Increased pressure inside the skull from conditions like idiopathic intracranial hypertension or hydrocephalus can push CSF through the bones or natural openings in the sinuses. Symptoms may develop gradually or suddenly.
5. Spontaneous leak
Sometimes a CSF leak occurs spontaneously for unknown reasons in the absence of trauma, tumors, or surgery. Potential factors include structural weaknesses, increased pressure, bone degeneration, or connective tissue disorders. Symptoms come on gradually.
Symptoms of Spinal Fluid Leaking From the Nose
The most common symptoms of a CSF leak include:
- Clear fluid dripping from the nose (rhinorrhea)
- Metallic, salty, or sweet taste in the mouth
- Fluid pooling in the back of the throat
- Nasal congestion or runny nose
- Headache
- Nausea
- Vomiting
- Vision changes
- Light or noise sensitivity
- Memory or concentration problems
- Neck stiffness
Lying flat typically makes symptoms worse. The drainage may be continuous or intermittent depending on the cause. Other associated symptoms can include fever, sinus infection, meningitis, or brain abscess.
When Spinal Fluid Is Colored
While normal CSF is clear and colorless, several factors can cause it to take on color when leaking from the nose:
Pink, Red, or Brown:
The most common cause of reddish nasal drainage with a CSF leak is a concurrent nosebleed. Even a small amount of blood mixing with the leaking CSF can turn it pink, red, or brown. The bleeding may originate from ruptured capillaries along the nasal mucosa or a head injury.
Yellow or Green:
A yellow or green CSF leakage indicates an infection like viral or bacterial meningitis inflaming the membranes around the brain and spinal cord. The infected CSF takes on a turbid, cloudy appearance.
| Color | Cause |
|---|---|
| Pink, red, or brown | Nosebleed mixing with clear CSF |
| Yellow or green | Bacterial or viral meningitis infection |
| Red | Bleeding in brain after trauma |
| Yellow | Previous hemorrhage turning CSF xanthochromic |
Red:
Fresh blood turning CSF red may indicate bleeding in the brain following a head injury. Blood gradually breaks down over time, causing the CSF to take on a yellowish hue.
Yellow:
A prior brain bleed (subarachnoid hemorrhage) can release bilirubin as red blood cells break down. This causes the CSF to become xanthochromic, or yellow-tinged.
Diagnosing a CSF Leak
If a CSF leak is suspected, several diagnostic tests may be performed:
- Nasal endoscopy – A tiny camera on a tube examine the nasal cavities for drainage sites.
- CT scan – CT imaging helps locate skull base defects.
- MRI – MRI provides detailed images of soft tissues and can identify brain abnormalities.
- LP test – Analyzing CSF sample from lumbar puncture can confirm leak.
- Drainage collection – Collecting nasal drainage to test for CSF beta-2 transferrin protein.
- Intrathecal fluorescein – Injecting dye into CSF to trace leak under blue light.
Identifying the exact location of the leak guides appropriate treatment. Associated symptoms may also require evaluation for infection, increased intracranial pressure, or neurologic injury.
Treating a CSF Leak
The best treatment approach depends on the underlying cause and severity of the CSF rhinorrhea. Options may include:
Conservative Measures:
Bed rest, head elevation, hydration, and avoidance of straining activities may allow small traumatic or spontaneous leaks to seal on their own. Over-the-counter pain relievers can provide symptom relief.
Medications:
Oral or intravenous antibiotics treat meningitis infections. Steroids help reduce swelling. Medications that reduce CSF production are sometimes used for high-pressure hydrocephalus.
Surgery:
Surgical repair seals the CSF leak. This may involve grafting fat, muscle, cartilage, or synthetic material over the skull base defect. Endoscopic surgery through the nasal cavities is often sufficient for smaller leaks. Larger leaks require a craniotomy procedure.
Lumbar Drain:
A lumbar drain can divert CSF from the leak site to facilitate healing. This involves inserting a spinal catheter to drain excess CSF into the abdomen where it can be reabsorbed.
Proper treatment closes the leak and relieves associated symptoms. It is important to monitor and manage any underlying condition, such as hydrocephalus or intracranial hypertension. Delaying repair of a persistent CSF leak raises the risk of serious complications like meningitis infection or brain herniation.
Preventing CSF Leaks
It is not always possible to prevent a CSF leak, but the following measures may help lower risk:
- Wear seatbelts and protective gear during contact sports.
- Treat any head injury promptly.
- Follow safety precautions at work and home to avoid falls.
- Manage medical conditions that increase intracranial pressure.
- Carefully follow post-surgical instructions after brain, sinus, or skull base procedures.
Let the doctor know if you experience any suspicious nasal drainage after an injury or surgery. Early intervention improves outcomes with CSF leaks. Seek prompt medical attention for any concerning nasal discharge, headache, vomiting, vision issues, or other possible CSF leak symptoms.
Conclusion
Cerebrospinal fluid leaking from the nose is usually clear and colorless. But it may appear pink, red, yellow, green, or brown in certain situations like a nosebleed, infection, or brain bleed. Regardless of color, a CSF leak indicates an underlying problem requiring prompt evaluation. Diagnostic testing identifies the source so appropriate treatment can seal the leak and prevent complications. While not every CSF leak is preventable, following safety precautions, managing risk factors, and seeking timely care after head trauma or surgery can improve outcomes.