Runny Nose Caused by Brain Fluid Leak

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Everyone has experienced rhinorrhea, commonly known as a runny nose, at some point. Most often, a runny nose is caused by allergic rhinitis or the common cold.

Other causes of runny noses include gustatory rhinitis caused by cold weather or eating spicy foods, and vasomotor rhinitis caused by nasal irritants such as strong odors or weather changes.

These common causes of a runny nose either last a short period of time, such as with the common cold, or respond to the treatment with allergy medications, such as oral antihistamines, nasal corticosteroid sprays, or nasal anticholinergic sprays.

Some people may experience runny noses all the time that don't respond to any type of allergy medication; these people may have a rare condition called cerebrospinal fluid (CSF) rhinorrhea, caused by a leaking of brain fluid out of the nose.

A woman blowing nose with a handkerchief
Eugenio Marongiu / Getty Images


CSF rhinorrhea is an unusual condition that may occur after a traumatic head injury, as a complication of sinus or brain surgery, or as a result of a tumor or congenital birth defect. It can also be idiopathic (with no known cause) or due to increased intracranial pressure.


People with CSF rhinorrhea might complain of a runny nose that gets worse with a change in position (such as standing up) or with Valsalva maneuver (straining or lifting heavy objects).

The liquid in CSF rhinorrhea is thin and clear, and an affected person might notice a sweet or salty taste due to the increased glucose and electrolytes present in cerebrospinal fluid.


If a person has CSF rhinorrhea, it is important that the condition is corrected because there is an increased risk of developing bacterial meningitis which is a life-threatening infection around the brain.

Bacteria can spread from within the nasal passages and sinuses through the hole in the dura (the tissue that surrounds the brain and spinal cord) and into the lining around the brain, resulting in meningitis.

People who have developed more than one episode of bacterial meningitis should be evaluated for possible CSF rhinorrhea, as well as an evaluation for primary immunodeficiency by a clinical immunologist.


While CSF rhinorrhea is not a common condition, this diagnosis should be considered in a person who has a chronic runny nose, without other symptoms of allergic rhinitis, that doesn't respond to typical allergy medications. Anyone who has had repeated episodes of bacterial meningitis should also be evaluated for CSF rhinorrhea.

The most accurate way to diagnose CSF rhinorrhea is to show the presence of beta-2 transferrin in the nasal discharge. Once CSF rhinorrhea is suspected or confirmed by the presence of beta-2 transferrin, the leak needs to be localized for the purpose of surgical correction.

Various methods have been used to localize the CSF rhinorrhea, most commonly brain MRI or a nuclear medicine scan with Indium 111.


Once the site of the CSF is localized, it can be surgically corrected using a number of different techniques. Most commonly, the CSF leak is fixed through nasal endoscopy using a skin or bone graft to plug the hole.

A Word From Verywell

If you've experienced a runny nose without other allergy symptoms, or a runny nose that doesn't get better with time or with allergy medications, ask your healthcare provider if you could have a CSF leak. This would be especially important if you had a head injury before a runny nose started, or if you have ever contracted meningitis.

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  1. Kerr JT, Chu FWK, Bayles SW. Cerebrospinal Fluid Rhinorrhea: Diagnosis and Management. Otolaryngol Clin N Am. 2005;38:597-611. DOI:


  2. Mathias, Tiffany et al. “Contemporary Approach to the Diagnosis and Management of Cerebrospinal Fluid Rhinorrhea.” The Ochsner journal vol. 16,2 (2016): 136-42. PMID: 27303222