When cerebrospinal fluid pressure is too high or low, people can experience headache. High cerebrospinal fluid (CSF) pressure is referred to as ‘idiopathic intracranial hypertension’, while headache caused by low CSF pressure is often called a ‘post-dural puncture headache’.
Idiopathic intracranial hypertension (IIH)
Idiopathic intracranial hypertension is a disorder in which people have elevated cerebrospinal fluid (CSF) pressure. When IIH develops, people either experience the onset of a new headache or the significant worsening of a pre-existing headache. Sometimes the headache is accompanied by ringing in the ears (tinnitus) or visual loss, particularly around the edges (peripheries) of vision. This latter symptom is caused by swelling of the optic disc (papilloedema), which if left untreated can cause permanent vision loss. IIH is more likely to affect women during their reproductive years and is also more common in people who are overweight. Some medications such as tetracycline antibiotics, steroids/growth hormones, and anti-acne medication can also cause IIH. The pain can be treated by removing some of the CSF to reduce pressure, however, if there is an underlying condition causing the fluid to build up, this needs to be investigated to effectively treat the person.
Post-dural puncture headache (low cerebrospinal fluid pressure)
Headaches can be caused due to low cerebrospinal fluid (CSF) pressure following a spinal tap (also called a lumbar puncture). The headache is often accompanied by neck stiffness or hearing symptoms, and is exacerbated by sitting or standing up. This occurs because in the five days following a spinal tap, CSF can leak through the puncture hole and result in lower pressure around the brain. It can either spontaneously resolve by itself within two weeks or after sealing the leak with an epidural lumbar patch (injecting some of the person’s own blood around the site of the lumbar puncture to cause a blood clot to seal over the site of the leak).
Idiopathic Intracranial Hypertension – more detailed article
Spinal Cerebrospinal Fluid (CSF) Leak – Brain Foundation