COVID-19 Triggers Dangerous Brain Pressure Leading to Headaches Seen in Long COVID

Medical News: Over the past few years, COVID-19 has emerged not just as a respiratory illness but a multifaceted disease that leaves a devastating trail across the body - and one of the most alarming revelations now coming to light is its potential to cause increased pressure in the brain, medically known as intracranial hypertension (ICH). This serious condition can lead to a range of debilitating symptoms such as severe headaches, vision problems, confusion, seizures, and in extreme cases, irreversible brain damage or even death. Alarmingly, growing clinical evidence now links intracranial hypertension to both acute COVID-19 infections and Long COVID, especially in patients who report persistent headaches and migraine-like symptoms.


COVID-19 Triggers Dangerous Brain Pressure Leading to Headaches Seen in Long COVID

This Medical News report explores a series of disturbing case reports and clinical studies showing how the SARS-CoV-2 virus may be triggering this dangerous condition - even in individuals without the typical risk factors such as obesity or female gender. The implications of these findings are profound, as they open a new chapter in our understanding of Long COVID and why so many patients continue to suffer from headaches long after their infection seems to have cleared.
 
When Headaches Signal a Hidden Danger
For many COVID-19 patients, headaches may seem like just another unpleasant symptom among others. But in a growing number of cases, these headaches turn out to be much more than that - they’re actually signs of increased pressure inside the skull. This pressure can compress brain tissues, impede blood flow, and threaten the health of the optic nerves, potentially leading to vision loss or permanent neurological impairment.
 
Take, for example, the documented case of a previously healthy 45-year-old man in Ethiopia. After contracting COVID-19, he developed progressively worsening headaches, visual disturbances, and even projectile vomiting - classic signs of intracranial hypertension. A brain MRI revealed swelling around the optic nerves and signs of papilledema (optic disc swelling), and a lumbar puncture confirmed abnormally high cerebrospinal fluid (CSF) pressure. He was successfully treated with acetazolamide, a medication that reduces CSF production, and eventually recovered. What was particularly notable in his case was the complete absence of usual risk factors for idiopathic intracranial hypertension (IIH) - such as obesity or being female - which strongly pointed toward the virus itself as the underlying cause.
 
COVID-19 and a Hidden Epidemic of Brain Pressure
Though rare, these cases are not isolated. In Brazil, a multi-center study analyzed 56 hospitalized COVID-19 patients who underwent lumbar punctures due to neurological complaints. Thirteen of them had intense, daily headaches that prompted further evaluation. Of those, 11 had elevated CSF opening pressures, and six met the criteria for full-blown intracranial hypertension. Surprisingly, these patients showed no signs of infection in the brain, no meningitis, and no encephalitis - just unexp lained high intracranial pressure. Most had throbbing, holocranial headaches and visual disturbances, and several responded well to treatment with acetazolamide.
 
In one standout case from the same study, a 26-year-old woman developed intense headaches and visual blurring just days after flu-like symptoms. Lumbar puncture revealed a CSF pressure of 350 mmH₂O (well above the normal upper limit of 200 mmH₂O), despite a completely normal brain scan. Again, treatment with acetazolamide helped alleviate symptoms, but the root cause was clear - COVID-19 had somehow disturbed the brain’s delicate fluid balance, leading to ICH.
 
What’s Causing This Pressure Build-Up?
Researchers and clinicians are still piecing together the exact mechanisms, but several theories are gaining traction. First, SARS-CoV-2 appears to trigger widespread inflammation throughout the body - including in the brain. This inflammatory response may impair the normal production and absorption of cerebrospinal fluid, leading to a build-up of pressure.
 
Second, COVID-19 has been shown to cause a state of hypercoagulability - a tendency for the blood to clot more easily. This can increase the risk of cerebral venous sinus thrombosis (CVST), a condition where blood clots block venous drainage from the brain, thereby elevating intracranial pressure. However, in many of the documented cases, no blood clots were found, raising the possibility that even microvascular changes or a hyperviscous blood state caused by the virus might be enough to impede CSF drainage and trigger ICH.
 
Optic nerve sheath diameter (ONSD) studies from Turkey have shown that patients with COVID-19 and headaches have significantly wider optic nerve sheaths - a reliable non-invasive marker of elevated intracranial pressure. This supports the clinical suspicion that SARS-CoV-2 can indeed cause ICH in a subset of patients.
 
Post-COVID Brain Pressure May Linger for Months
Perhaps even more concerning is the fact that intracranial hypertension doesn’t always go away after the acute phase of the infection ends. In a case reported by neurologists in the United States, a 75-year-old woman experienced persistent, debilitating headaches for six months following a mild case of COVID-19. Standard painkillers failed to help. A brain compliance test revealed dangerously poor brain pressure regulation, and her symptoms only improved after a lumbar puncture and treatment with acetazolamide. This suggests that, in some cases, SARS-CoV-2 may cause long-term changes in CSF dynamics, potentially contributing to the chronic headaches seen in Long COVID.
 
Another case in Turkey involved a 40-year-old woman who developed severe headaches and vision loss more than two weeks after recovering from COVID-19. She had no prior history of such issues. Her CSF pressure was alarmingly high at 410 mmH₂O. Although she initially refused surgery, her condition improved with aggressive medical treatment including acetazolamide. This case illustrates how COVID-19 can precipitate ICH even in the later stages of the illness and even in individuals with pre-existing risk factors such as obesity.
 
Why This Matters
Headaches, especially when persistent, severe, or accompanied by visual changes, are often brushed off or misdiagnosed—especially in post-COVID cases. However, the data clearly show that increased intracranial pressure is a significant and under-recognized consequence of both acute COVID-19 and Long COVID. Left untreated, intracranial hypertension can result in permanent complications such as optic nerve damage, brain herniation, or even death.
 
This condition is particularly insidious because standard CT scans and MRIs may not always reveal it. Diagnosis often requires a lumbar puncture to measure CSF pressure or ultrasound imaging of the optic nerve. Treatment may involve medication like acetazolamide, surgical interventions in severe cases, and close neurological and ophthalmologic monitoring.
 
Conclusion
The mounting clinical evidence leaves little room for doubt: COVID-19 has the capacity to induce intracranial hypertension in a significant number of patients, including those without traditional risk factors. From persistent headaches to vision problems and even neurological decline, the symptoms tied to this pressure build-up inside the skull are too severe to ignore. Alarmingly, this phenomenon can occur not only during the acute phase of infection but even weeks or months afterward, making it a hidden threat within the broader Long COVID syndrome.

Healthcare providers need to stay vigilant and consider idiopathic intracranial hypertension (IIH) in any COVID-19 or Long COVID patient presenting with headaches, especially when accompanied by nausea, blurred vision, vomiting, or behavioral changes. More research is urgently needed to unravel the underlying mechanisms - whether inflammation, microvascular damage, or CSF absorption defects - and to determine which patients are most at risk.
 
If you or a loved one is experiencing persistent headaches after COVID-19, especially with visual symptoms or nausea, don’t delay seeking medical evaluation. Early diagnosis and proper treatment could prevent permanent vision loss or worse.
 
References:
https://jmedicalcasereports.biomedcentral.com/articles/10.1186/s13256-024-04519-x
 
https://journals.sagepub.com/doi/10.1177/0333102420965963
 
https://journals.lww.com/ijo/fulltext/2021/06000/intracranial_hypertension_and_visual_loss.59.aspx
 
https://www.neurology.org/doi/10.1212/WNL.0000000000205027
 
https://www.neurology-asia.org/system/index.php/neuro/article/view/594
 
https://www.medtextpublications.com/open-access/neurological-sequelae-in-idiopathic-intracranial-hypertension-and-covid-19-patients-a-1687.pdf
 
https://link.springer.com/article/10.1007/s12070-022-03303-x
 
https://www.gacetamedicaboliviana.com/index.php/gmb/article/view/705
 
https://link.springer.com/article/10.1007/s13760-021-01818-8
 
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