Print OverviewCerebrospinal fluid (CSF) surrounds your brain and spinal cord and provides a cushion to protect them from injury. The spinal cord and CSF are surrounded by three layers of membranes. A CSF leak occurs when there is a hole or tear in the outermost layer of these membranes (dura mater), which allows some of the fluid to escape. There are two distinct types of CSF leaks with different symptoms, causes and treatments. These are spinal CSF leaks and cranial CSF leaks. A spinal CSF leak occurs anywhere in the spinal column. A cranial CSF leak occurs in the skull. The most common symptom of a spinal CSF leak is a headache, while a cranial CSF leak causes symptoms such as clear fluid leaking from the nose or ear. Some CSF leaks may heal with conservative treatments such as bed rest. Many CSF leaks need a blood patch to cover the hole or surgery to repair the leak. SymptomsSymptoms vary between spinal and cranial CSF leaks. Spinal CSF leaksThe most common symptom of a spinal CSF leak is headache. These headaches usually: Cause pain in the back of the head Improve when lying down Worsen when standing up May start or worsen with exertion (such as coughing or straining) Rarely, start suddenly ("thunderclap" headache) Other symptoms of spinal CSF leaks may include: Neck or shoulder pain Ringing in the ears (tinnitus) Changes in hearing Dizziness Nausea or vomiting Changes in vision Changes in cognition or behavior Cranial CSF leaksCranial CSF leak symptoms may include: Clear, watery drainage from the nose or ear (on one side) Hearing loss A metallic taste in the mouth Meningitis Request an appointment CausesSpinal CSF leaks may be caused by: A lumbar puncture (spinal tap) An epidural in the spine for pain relief, such as during labor and delivery An injury to the head or spine Bone spurs along the spine Abnormalities of the dura mater around the nerve roots in the spine Abnormal connections between dura mater and veins (CSF-venous fistulas) Prior surgery on the spine Cranial CSF leaks may be caused by: A head injury Increased pressure in the brain Poorly functioning shunt Malformations of the inner ear Sometimes CSF leaks develop after very minor events: Sneezing Coughing Straining to have a bowel movement Lifting heavy objects Falling Stretching Exercise Sometimes a CSF leak doesn't have a known cause (spontaneous CSF leak). Risk factorsRisk factors for spinal CSF leaks include: Having a previous surgery or procedure on or around the spine Connective tissue disorders such as Marfan syndrome or Ehlers-Danlos syndrome Risk factors for cranial CSF leaks include: Having a previous surgery on or around the skull Obesity Obstructive sleep apnea Head trauma Tumor at the skull base Abnormalities of the skull base or inner ear ComplicationsPossible complications of a cranial CSF leak that is left untreated include meningitis and air entering the spaces surrounding the brain (tension pneumocephalus). By Mayo Clinic Staff CSF leak (Cerebrospinal fluid leak) care at Mayo Clinic Request an appointment Diagnosis & treatment Oct. 26, 2021 Print Show references Spinal cerebrospinal fluid leak. AskMayoExpert. Mayo Clinic; 2021. Sun-Edelstein C, et al. Spontaneous intracranial hypotension: Pathophysiology, clinical features and diagnosis. https://www.uptodate.com/contents/search. Accessed July 20, 2021. Sun-Edelstein C, et al. Spontaneous intracranial hypotension: Treatment and prognosis. https://www.uptodate.com/contents/search. Accessed July 20, 2021. Cranial/base of skull CSF leak. AskMayoExpert. Mayo Clinic; 2021. Schievink WI. Spontaneous spinal cerebrospinal fluid leaks and intracranial hypotension. JAMA. 2006; doi: 10.1001/jama.295.19.2286. Jankovic J, et al. Headache and other craniofacial pain. In: Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Elsevier; 2022. https://www.clinicalkey.com. Accessed July 28, 2021. Nagel SJ, et al. Cerebrospinal fluid disorders and transitional neurosurgery. In: Youmans and Winn Neurological Surgery. 7th ed. Elsevier; 2017. https://www.clinicalkey.com. Accessed July 28, 2021. Chan SM, et al. Intracranial hypotension and cerebrospinal fluid leak. Neuroimaging Clinics of North America. 2019; doi:10.1016/j.nic.2019.01.002. Braswell-Pickering B. Allscripts EPSi. Mayo Clinic. August 9, 2021. Related Associated Procedures Lumbar puncture (spinal tap) MRI CSF leak (Cerebrospinal fluid leak)Symptoms&causesDiagnosis&treatmentDoctors&departmentsCare atMayoClinic Advertisement Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. Advertising & Sponsorship Policy Opportunities Ad Choices Mayo Clinic Press Check out these best-sellers and special offers on books and newsletters from Mayo Clinic Press. Mayo Clinic on Incontinence - Mayo Clinic PressMayo Clinic on IncontinenceThe Essential Diabetes Book - Mayo Clinic PressThe Essential Diabetes BookMayo Clinic on Hearing and Balance - Mayo Clinic PressMayo Clinic on Hearing and BalanceFREE Mayo Clinic Diet Assessment - Mayo Clinic PressFREE Mayo Clinic Diet AssessmentMayo Clinic Health Letter - FREE book - Mayo Clinic PressMayo Clinic Health Letter - FREE book CON-20426989 Patient Care & Health Information Diseases & Conditions CSF leak (Cerebrospinal fluid leak)