The Short Answer Educational content only. Any suspected concussion warrants medical evaluation. New, severe, or changing headache after head injury warrants prompt assessment by a physician, neurologist, or headache specialist to confirm the diagnosis and exclude dangerous causes. Consult a concussion-experienced clinician for individualized care. Concussion can trigger hemicrania continua, a continuous one-sided headache with autonomic features that responds completely and specifically to indomethacin (Ashina et al., 2019). Hemicrania continua produces a persistent, strictly one-sided headache that is present continuously, with superimposed flares that bring same-side autonomic signs such as tearing, nasal congestion, and eyelid changes, along with a sense of restlessness. Its defining feature is an absolute response to the anti-inflammatory medication indomethacin, which both confirms the diagnosis and treats the condition. After trauma, disruption of the trigeminal-autonomic pathways can produce this pattern. Recognizing it prompts an indomethacin trial that often resolves the pain. Hemicrania continua is a continuous one-sided headache with autonomic flares. It responds completely and specifically to indomethacin. The indomethacin response both confirms and treats it. What Hemicrania Continua Is Hemicrania continua is a trigeminal autonomic cephalalgia defined by a continuous, strictly one-sided headache that never fully goes away. On this constant background of moderate pain, flares of more severe pain occur, and during flares the person develops same-side autonomic features, tearing, redness, a running or blocked nostril, or a drooping eyelid, and often a sense of agitation or restlessness. The pain stays on the same side throughout and does not switch sides. The word continua captures the key feature: unlike cluster headache or paroxysmal hemicrania, which come in discrete attacks, hemicrania continua is continuous, a baseline headache that is always present with flares on top. This continuous one-sided pattern with autonomic flares is what raises suspicion of the diagnosis. The Defining Indomethacin Response Hemicrania continua has an unusual and defining property: it responds completely to indomethacin, a specific anti-inflammatory medication, and to essentially nothing else as reliably. A complete resolution of the headache on an adequate dose of indomethacin is so characteristic that it is part of the diagnostic definition. This absolute response is a diagnostic test in itself. A supervised indomethacin trial that abolishes the headache confirms hemicrania continua, and failure to respond points away from it toward another diagnosis. Because indomethacin both defines and treats the disorder, recognizing the continuous one-sided pattern and arranging a trial is the crucial step. Without recognition, people can spend years on ineffective migraine or tension-type treatments for a headache that would resolve on the correct medication. How Concussion Can Trigger It Head trauma is a recognized trigger for hemicrania continua. The injury can disrupt the trigeminal-autonomic pathways whose activation produces the continuous one-sided pain and the autonomic flares. Post-traumatic hemicrania continua appears after the injury and carries the same defining features, including the indomethacin response, as the primary form. As with the other trigeminal autonomic cephalalgias, the specific phenotype reflects involvement of these particular pathways rather than diffuse injury alone, which is why the headache is recognizable and, importantly, treatable with a specific medication. Symptom Presentation Continuous, strictly one-sided headache that is always present Flares of more severe pain on the constant background Same-side autonomic features during flares: tearing, congestion, eyelid changes A sense of restlessness or agitation during flares Pain that stays on the same side and does not switch Onset after a head injury Complete resolution on an adequate dose of indomethacin Assessment A neurologist or headache specialist recognizes the continuous one-sided headache with autonomic flares and arranges a supervised indomethacin trial, which confirms the diagnosis when the headache resolves completely. Because the disorder can rarely be mimicked by a secondary cause, particularly after head injury, brain imaging is generally obtained to exclude a structural lesion before or alongside the trial. The specialist distinguishes hemicrania continua from other continuous headaches and from the episodic trigeminal autonomic cephalalgias, since the treatments differ. Treatment Approach Indomethacin is the treatment as well as the diagnostic test. An adequate dose typically abolishes the headache, and the clinician then finds the lowest effective maintenance dose. Because indomethacin can irritate the stomach and affect the kidneys, it is used with gastric protection and monitoring, and a specialist manages long-term use. Some people need it only for a period, while others require ongoing treatment. For people who cannot tolerate indomethacin, a specialist considers alternative medications, though none matches its reliability. Addressing coexisting contributors, the cervical component, sleep, and autonomic regulation, supports overall headache stability, and avoiding medication overuse from other acute treatments protects against a superimposed daily headache. The central point remains that recognizing the pattern and trialing indomethacin is what transforms this otherwise stubborn headache. Post-traumatic headache often has a cervical and autonomic component that responds to daily mobility and nervous system regulation alongside medical care. Start your 3-day free trial to build a supportive routine. Supporting Mobility Routine JME 155 Diaphragmatic breathing lowers the sympathetic drive that fuels headache and supports steady cerebral blood flow. Ten slow breaths, several times daily. JME 14 Chin tucks activate deep cervical flexors and reduce the upper cervical tension that refers pain to the head. Ten repetitions with 5-second holds. JME 1 Cervical rotation restores segmental mobility at the joints that refer pain into headache through the trigeminocervical nucleus. Ten repetitions per direction. JME 15 Cervical lateral flexion addresses side-bending restriction that sustains neck-driven headache. Ten repetitions per side. JME 16 Cervical flexion and extension restore sagittal mobility restricted by suboccipital guarding. Eight slow repetitions. JME 2 Cervical retraction reinforces a neutral head position that reduces the postural strain feeding headache. Ten repetitions per set. JME 150 Thoracic rotation restores mid-back motion needed for full cervical range and relaxed upright posture. Eight repetitions per direction. JME 227 Overhead reach opens the thoracic spine and reduces the compensatory upper cervical extension that drives headache. Ten repetitions with controlled tempo. Start your 3-day free trial for joint-specific mobility programming that addresses the cervical and autonomic contributors to post-traumatic headache. Common Mistakes Missing the diagnosis and treating it as migraine or tension-type headache for years Never arranging the indomethacin trial that confirms and treats it Using indomethacin without gastric protection and monitoring Overlooking a structural cause after head injury before the trial Allowing medication overuse from other acute treatments to add a daily headache Progression A specialist recognizes the continuous one-sided pattern with autonomic flares, excludes a structural cause, and arranges a supervised indomethacin trial. Complete resolution confirms the diagnosis and establishes treatment, with the lowest effective dose maintained under monitoring. Cervical, sleep, and autonomic support supplement care. Some people need indomethacin only temporarily, while others require ongoing treatment. What is hemicrania continua? It is a trigeminal autonomic cephalalgia defined by a continuous, strictly one-sided headache with flares that bring same-side autonomic features and restlessness. Its defining property is a complete response to indomethacin. The pain is always present on one side and does not switch sides. Why is indomethacin so important for hemicrania continua? Hemicrania continua responds completely to indomethacin and to essentially nothing else as reliably, so the response is part of the diagnostic definition. A supervised indomethacin trial that abolishes the headache confirms the diagnosis and provides the treatment at the same time, which is why recognizing the pattern and arranging the trial is crucial. Can a concussion cause hemicrania continua? Head trauma is a recognized trigger. The injury can disrupt the trigeminal-autonomic pathways that produce the continuous one-sided pain and autonomic flares. Post-traumatic hemicrania continua carries the same features as the primary form, including the defining indomethacin response. How is hemicrania continua different from a continuous migraine? Hemicrania continua is strictly one-sided with same-side autonomic features during flares and, crucially, resolves completely with indomethacin. Continuous or chronic migraine lacks this absolute indomethacin response and often differs in laterality and features. The indomethacin response is the key distinguishing test. Is indomethacin safe for long-term use? Indomethacin can irritate the stomach and affect the kidneys, so it is used with gastric protection and monitoring under specialist guidance. Some people need it only for a period, while others require ongoing treatment at the lowest effective dose. A specialist balances the benefit against the risks over time. Red Flags Requiring Urgent Evaluation The following warrant same-day emergency evaluation rather than routine care. Sudden severe headache that peaks within seconds to minutes Headache with fever, neck stiffness, or rash New weakness, numbness, slurred speech, or facial droop New vision loss, double vision, or a persistent visual change Progressive worsening headache over days to weeks Headache with confusion, drowsiness, or repeated vomiting Headache with seizure or loss of consciousness Sudden severe neck pain with neurological symptoms, suggesting arterial dissection These features can indicate a dangerous cause and take priority over any headache-specific diagnosis. Absence of red flags supports outpatient evaluation and management. Medication Overuse Headache Frequent use of acute headache medication can produce medication overuse headache, where the treatment itself sustains a daily or near-daily headache. This is common after concussion, when frequent pain drives frequent medication use. As a general guide, using simple analgesics on 15 or more days per month, or triptans, combination analgesics, or opioids on 10 or more days per month, raises the risk. Preventive treatment and careful limits on acute medication, guided by a clinician, break the cycle. Recognizing medication overuse is essential, because it can mimic or worsen any post-traumatic headache pattern. Why a Precise Diagnosis Matters Post-traumatic headache is not one condition. It takes on the features of recognized primary headache disorders, and each has a specific, sometimes highly specific, treatment. Some headaches respond dramatically to one particular medication, others need targeted preventives, and others improve with cervical and autonomic treatment. A precise diagnosis by a physician, neurologist, or headache specialist, using the criteria of the International Classification of Headache Disorders, directs the person to the treatment most likely to work and avoids prolonged trial and error. Multidisciplinary Care and the Cervical Contribution Post-traumatic headache frequently has more than one driver. A cervical contribution from the neck is common, since the upper cervical joints and nerves refer pain to the head through the trigeminocervical nucleus, the same brainstem region where neck and head pain signals converge. Autonomic dysregulation, sleep disturbance, mood, and medication overuse each add to the picture. Coordinated care works best: a headache specialist or neurologist for diagnosis and medication, a physical therapist for the cervical and postural contribution, and attention to sleep, mood, and autonomic regulation. Treating the neck and nervous system alongside medical management improves many post-traumatic headaches that medication alone does not fully control. References Ashina, H., et al. (2019). Post-traumatic headache: epidemiology and pathophysiological insights. Nature Reviews Neurology, 15(10), 607-617. PubMed Headache Classification Committee of the International Headache Society (IHS). (2018). The International Classification of Headache Disorders, 3rd edition. Cephalalgia, 38(1), 1-211. PubMed Patricios, J. S., et al. (2023). Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport, Amsterdam, October 2022. British Journal of Sports Medicine, 57(11), 695-711. PubMed