Exertion Headaches: When to Worry

Exertion headaches: when to worry (and when not to)

A headache that starts during or after exercise is called an exertion headache. Most are benign and resolve on their own. A small number are warning signs of something serious that needs emergency evaluation right away. Knowing the difference could save your life — or spare you an unnecessary ER visit.

Key takeaways

• Primary exertion headache is a recognized, benign condition with no underlying cause — but it requires evaluation on the first occurrence to rule out something dangerous.
• The single most important red flag is thunderclap onset: pain that peaks within seconds and feels like the worst headache of your life.
• Secondary exertion headache — caused by bleeding in or around the brain, arterial dissection, or reversible cerebral vasoconstriction syndrome — is less common but carries significant risk.¹
• A 2025 systematic review confirmed that primary exertion headache affects 1% to 26% of adults depending on the population studied, with a predilection for younger adults and females.²
• Indomethacin taken before exercise and beta-blockers daily are the mainstays of prevention for people with recurrent primary exertion headache.

What is an exertion headache?

An exertion headache is any headache brought on by strenuous physical activity. The term covers a spectrum: from benign, predictable pain that resolves with rest, to a catastrophic headache that signals bleeding inside the skull.

The ICHD-3 — the International Headache Society's official classification — defines primary exercise headache (PEH) as at least two episodes occurring during or after strenuous exercise, lasting five minutes to 48 hours, and not better explained by another diagnosis.⁴ It is typically bilateral (both sides of the head) and pulsating. Triggers include running, weightlifting, cycling, rowing, swimming, and high-intensity interval training.

The critical caveat from the ICHD-3 is explicit: on the first occurrence of a headache with these characteristics, subarachnoid hemorrhage, arterial dissection, and reversible cerebral vasoconstriction syndrome (RCVS) must be excluded.⁴ Primary exertion headache is a diagnosis of exclusion — the benign label only applies once the dangerous causes have been ruled out.

What is the difference between primary and secondary exertion headache?

This distinction is the most important thing in this article.

Primary exertion headache has no underlying cause. The prevailing mechanism involves increased intracranial venous pressure during exercise — strenuous activity raises intrathoracic pressure, which transmits back through the jugular veins into the skull, increasing pressure and triggering the headache.¹ A recent study found that patients show a much higher rate of internal jugular venous valve incompetence than healthy controls (70% versus 20%), pointing to the possibility that backward flow through the jugular veins causes venous congestion in the brain, which may contribute to how this condition develops.⁴

A 2023 update in Cephalalgia noted that patients with primary exertion headache also tend to be young, with frequent comorbid migraine and a predilection for females in population surveys.¹ The condition is benign, self-limited in many patients, and responds well to indomethacin.³

Secondary exertion headache is caused by an underlying condition. The most serious possibilities include:¹³

• Subarachnoid hemorrhage (SAH) — bleeding around the brain from a ruptured aneurysm
• Reversible cerebral vasoconstriction syndrome (RCVS) — sudden spasm of brain arteries
• Cervical artery dissection — a tear in the wall of the carotid or vertebral artery
• Cardiac cephalgia — headache as the only symptom of myocardial ischemia
• Intracranial hypertension or structural lesion

These conditions are less common than primary exertion headache, but the consequences of missing them are severe. Secondary causes cannot be reliably excluded on clinical grounds alone — imaging is required.

Red flags: when to go to the emergency room immediately

Some features of a headache during or after exercise require emergency evaluation the same day. Do not wait to see if the headache improves.

Call 911 or go to the nearest emergency room immediately if the headache:

• Peaks within seconds — this thunderclap pattern is the most important warning sign of subarachnoid hemorrhage⁵
• Feels like the worst headache of your life
• Is accompanied by neck stiffness or pain
• Is accompanied by confusion, altered consciousness, or difficulty speaking
• Is accompanied by vision changes, double vision, or vision loss
• Is accompanied by weakness or numbness on one side
• Is accompanied by fever
• Is accompanied by shortness of breath or chest pain (which may indicate cardiac cephalgia)¹
• Resolves partially and then returns
• Is your first exercise headache ever, especially if severe

The Ottawa SAH Rule — a validated clinical decision tool — identifies onset during exertion and thunderclap onset as criteria that mandate CT imaging.⁶ A headache that comes on explosively during lifting, straining, or sexual activity and peaks immediately should be treated as a potential SAH until imaging proves otherwise.

Modern multidetector CT performed within six hours of headache onset has close to 100% sensitivity for detecting subarachnoid hemorrhage.⁵ Sensitivity decreases to approximately 80% at three days and 50% at one week.⁷ Waiting even a few hours reduces the reliability of the test.

These are patterns, not rules. Any new or atypical exercise headache deserves clinical evaluation. A 2020 review in Current Neurology and Neuroscience Reports emphasized that older age at onset and prolonged headache duration are specific red flags for potential secondary causes.³

What to expect at your evaluation

If you present with a new or unusual exercise headache, your clinician will typically order:

CT scan without contrast — the first-line test to look for blood in or around the brain. Sensitivity approaches 100% within the first six hours after onset.⁵

Lumbar puncture (spinal tap) — performed after a normal CT if subarachnoid hemorrhage is still suspected, particularly if more than six hours have passed since headache onset. The 2023 American Heart Association guidelines on SAH management continue to recommend LP for patients presenting more than six hours after headache onset when CT is negative.⁸

CT angiography or MR angiography — to evaluate the blood vessels of the brain and neck for aneurysm, dissection, RCVS, or structural lesion.¹

Cardiac evaluation — in patients with cardiovascular risk factors or chest symptoms, an ECG and exercise stress test may be warranted to exclude cardiac cephalgia.³

Once secondary causes are excluded, primary exertion headache can be confirmed. A normal workup is genuinely good news — it means you have a manageable, benign condition.

How primary exertion headache is treated

There are no large randomized controlled trials for primary exertion headache. Guidance is based on case series and expert consensus.³

Indomethacin before exercise is the first-line pharmacological prevention, taken 30–60 minutes before anticipated exertion at doses of 25–150 mg.³ Indomethacin likely works by reducing intracranial pressure — it is a direct cerebral arteriolar vasoconstrictor, an effect not shared by other NSAIDs like ibuprofen or naproxen.⁹ A 2026 case report documented complete control of exercise headache in an adolescent athlete after dose titration of indomethacin, allowing full return to competitive running.⁹ Long-term daily use carries gastrointestinal risk; gastric protection is advised. Talk with a clinician before using it preventively.

Beta-blockers (propranolol, nadolol) are the preferred option when headache frequency is high, triggers are unpredictable, or NSAIDs are contraindicated.¹ Athletes should be aware that beta-blockers reduce maximal heart rate and may affect exercise tolerance.

Triptans may be used when a known exertion trigger cannot be avoided and neither indomethacin nor beta-blockers are suitable.¹

Non-pharmacological measures:

• Warm up gradually. A structured warm-up that raises heart rate incrementally — rather than starting at peak intensity — reduces the abrupt intracranial pressure change that appears to drive the headache.¹
• Stay well hydrated. Dehydration compounds both cardiovascular stress and migraine vulnerability.
• Avoid exercise in heat or at altitude. Both conditions amplify the cardiovascular demands of exertion and increase the risk of an episode.⁴
• Modify exercise type. If running consistently triggers headache but cycling does not, the lower-impact option may allow you to maintain fitness without the headache.

Natural course: Many people with primary exertion headache find the condition improves or resolves after months to years.¹ It is not a permanent diagnosis.

Is this different from exercise-triggered migraine?

Yes. Primary exertion headache and migraine triggered by exercise are distinct diagnoses, though they can coexist. Primary exertion headache begins during or immediately after exercise, is bilateral and pulsating, and resolves with rest — without the nausea, photophobia, phonophobia, or aura that characterize migraine. A 2025 systematic review confirmed that migraine comorbidity is common in people with primary exertion headache, and that female patients are more likely to be misdiagnosed as having migraine when PEH is the correct diagnosis.² A headache specialist can sort this out.

The bottom line

Most exertion headaches are benign. But the distinction between benign and dangerous cannot be made without evaluation. If you have ever had a headache during or after strenuous physical activity — especially if the onset was sudden or severe — bring that history to a clinician.

Getting the right diagnosis is the first step to getting the right care. Book an appointment with a Haven headache specialist and know for certain where your headache stands.

References

1. González-Quintanilla V, Madera J, Pascual J. Update on headaches associated with physical exertion. Cephalalgia. 2023;43(3). doi:10.1177/03331024221146989
2. Osiowski A, et al. Epidemiology of primary exercise headache: A systematic review and meta-analysis. Neuroepidemiology. Karger. 2025.
3. Upadhyaya P, Nandyala A, Ailani J. Primary exercise headache. Curr Neurol Neurosci Rep. 2020;20(5). PMC7160088.
4. Headache Classification Committee of the International Headache Society. ICHD-3 — Primary exercise headache.
5. Viera AJ, et al. Acute headache in adults: A diagnostic approach. Am Fam Physician. 2022;106(3).
6. Foley RW, et al. Subarachnoid haemorrhage rules in the decision for acute CT of the head: external validation in a UK cohort. ScienceDirect. 2024.
7. Subarachnoid hemorrhage workup. Medscape. Updated 2026.
8. Hoh BL, et al. 2023 Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage. AHA/ASA. Via EMCrit.
9. Ochiai K, et al. Pre-exercise indomethacin farnesil for primary exercise headache in an adolescent: A case report. ScienceDirect. 2026.

This article is for general education and is not medical advice. It is not a substitute for care from a qualified health professional. Always talk with your clinician before starting, stopping, or changing any treatment. If you have a sudden, severe headache, the worst headache of your life, or a headache with new symptoms like weakness, trouble speaking, or vision loss, seek emergency care right away.

Medically reviewed by: Karissa Secora, DMSc, PA-C, AQH., Haven Headache & Migraine Center and peer reviewed by Nada Hindiyeh, MD