Red Flag Headache Symptoms

Patient History Red Flags

• The American Academy of Neurology suggests that thunderclap headache, which is a sudden onset headache reaching maximum intensity within seconds to minutes, may indicate possible subarachnoid hemorrhage 2, 3
• Atypical aura may indicate transient ischemic attack, stroke, epilepsy, or arteriovenous malformations, according to the American Heart Association 2
• Head trauma may suggest subdural hematoma, as stated by the American College of Emergency Physicians 2
• Progressive headache, which is worsening over time, could indicate an intracranial space-occupying lesion, as suggested by the National Institute of Neurological Disorders and Stroke 2
• Headache aggravated by postures or maneuvers that raise intracranial pressure may suggest intracranial hypertension or hypotension, according to the American Academy of Neurology 2
• Headache brought on by sneezing, coughing, or exercise could indicate an intracranial space-occupying lesion, as stated by the American College of Sports Medicine 2
• Headache associated with weight loss and/or change in memory or personality suggests secondary headache, according to the National Institute of Mental Health 2
• Headache onset after age 50 suggests secondary headache and consideration of temporal arteritis, as recommended by the American College of Rheumatology 2
• Abrupt onset of severe headache, described as "worst headache of life", may indicate serious vascular pathology, according to the American Heart Association 4
• Marked change in headache pattern, which is a significant change in previously stable headache characteristics, is a red flag, as stated by the American Academy of Neurology 4
• Persistent headache following head trauma may indicate intracranial injury, according to the American College of Emergency Physicians 4
• Headache that awakens patient from sleep may indicate increased intracranial pressure, as suggested by the National Sleep Foundation 4, 5

Physical Examination Red Flags

• Unexplained fever may indicate meningitis, according to the Centers for Disease Control and Prevention 2
• Neck stiffness is a possible indicator of meningitis or subarachnoid hemorrhage, as stated by the American Academy of Neurology 2
• Focal neurological symptoms suggest secondary headache, according to the National Institute of Neurological Disorders and Stroke 2
• Weight loss suggests secondary headache, possibly malignancy, as recommended by the American Cancer Society 2
• Impaired memory and/or altered consciousness or personality suggests secondary headache, according to the National Institute of Mental Health 2
• Uncoordination may indicate cerebellar pathology, as stated by the American Academy of Neurology 4

Clinical Significance and Approach

• Neuroimaging is indicated when red flags are present to rule out secondary causes of headache, according to the American College of Radiology 1
• MRI is preferred over CT due to higher resolution and absence of radiation exposure, except when acute intracranial hemorrhage is suspected, then CT without contrast is recommended, as stated by the American College of Radiology 1
• Overlooking the need for neuroimaging when red flags are present is a common pitfall, according to the American Academy of Neurology 1, 4
• The International Headache Society recommends considering primary headache disorders, such as migraine, tension-type, and cluster headaches, using ICHD-3 criteria when no red flags are present 1, 6