When is a headache a migraine?

Migraine causes significant disability but is underdiagnosed and undertreated. Making an accurate diagnosis is key to improving outcomes for patients. At AAN 2021, Professor Hope O’Brien, University of Cincinnati College of Medicine, OH, provided expert tips on diagnosing migraine and differentiating it from potentially life-threatening secondary headache disorders.

Migraine causes significant disability but is not life-threatening. As a result, it is underdiagnosed and undertreated worldwide.1

Migraine is underdiagnosed worldwide

Migraine causes significant disability but is not life-threatening. As a result, it is underdiagnosed and undertreated worldwide.1


Primary headache vs secondary headache

Headaches are common, said Professor O’Brien, and almost 50% of adults have had at least one headache in the previous year.2 They are classified by the International Classification of Headache Disorders, 3rd edition as:

90% of headaches are primary headaches

  • Primary — eg, migraine, tension-type headache, trigeminal autonomic cephalalgia
  • Secondary due to a structural lesion or underlying disease
  • Painful cranial neuropathies, other facial pain and other headaches3

In 90% of cases, a headache is a primary headache, and the examination is normal.4

SNOOP is a screening mnemonic to exclude secondary headache

Secondary headaches may be life-threatening, however, noted Professor O’Brien, and need further investigation and neuroimaging.5 They must be excluded when diagnosing migraine. SNOOP is a helpful screening mnemonic highlighting the red flags, which are:

  • Systemic signs and disorders
  • Neurologic symptoms
  • Onset that is new or changed and over 50 years of age
  • Onset as a thunderclap headache
  • Papilledema, pulsatile tinnitus, positional provocation, precipitated by exercise5

Neuroimaging is not indicated for typical uncomplicated episodic or chronic migraine

Neuroimaging is also required for headaches diagnosed as:

  • Episodic or chronic migraine without aura accompanied by an abnormal neurologic examination
  • Migraine with aura accompanied by an atypical or complex aura
  • Trigeminal autonomic cephalalgia
  • Traumatic headache6

Professor O’Brien also noted the importance of the physical examination and paying attention to extracranial structures to exclude other diagnoses, for example sensitive scalp arteries suggesting temporal arteritis and impaired neck mobility suggesting meningeal irritation.7


Diagnosing migraine — the history is key

Stress is a common trigger

A thorough history is key in the diagnosis of migraine, said Professor O’Brien.

Important clinical features include its temporal pattern, location and radiation, nature (eg, throbbing), severity and intensity, associated features (eg, nausea, vomiting, aura), and aggravating factors (eg, light, sound, activity).7

Professor O’Brien highlighted that although usually unilateral, migraine headaches can be bilateral, and may be associated with cranial autonomic symptoms,3 and that stress is a common trigger.8

If two of the three PIN predictors are present, the positive predictive value for a diagnosis of migraine is 93%

She also highlighted the “PIN” screening test for migraine9 based on the following three important predictors of migraine:

  • Photophobia
  • Impairment/intensity
  • Nausea

When two of these three “PIN” predictors are present, the positive predictive value for a diagnosis of migraine is 93%.9

Additional diagnostic clues for a diagnosis of migraine include the presence of comorbid medical conditions with potentially shared pathophysiologic factors, for example asthma10 and a family history of migraine or other primary headache.7


Our correspondent’s highlights from the symposium are meant as a fair representation of the scientific content presented. The views and opinions expressed on this page do not necessarily reflect those of Lundbeck.


1. Ryvlin P, et al. Current clinical practice in disabling and chronic migraine in the primary care setting: results from the European My-LIFE anamnesis survey. BMC Neurology 2021;21:1.

2. World Health Organization. Headache disorders. 2016. Available at https://www.who.int/news-room/fact-sheets/detail/headache-disorders. Accessed 14 Jun 21.

3. Headache Classification Committee of the International Headache Society (IHS). International Classification of Headache Disorders, 3rd edition. Cephalalgia 2018;38:1–211.

4. Dodick D. Pearls: headache. Semin Neurol 2010;30:74–81.

5. Smith JH. Ruling out secondary headache. Pract Neurol 2018. Available at https://practicalneurology.com/articles/2018-mar-apr/ruling-out-secondary-headache. Accessed 14 Jun 21.

Country selection
We are registering that you are located in Brazil - if that's correct then please continue to Progress in Mind Brazil
You are leaving Progress in Mind
Please confirm your email
We have just sent you an email, with a confirmation link.
Before you can gain full access - you need to confirm your email.
The information on this site is exclusively intented for health care professionals.
All the information included in the Website is related to products of the local market and, therefore, directed to health professionals legally authorized to prescribe or dispense medications with professional practice. The technical information of the drugs is provided merely informative, being the responsibility of the professionals authorized to prescribe drugs and decide, in each concrete case, the most appropriate treatment to the needs of the patient.
Register for access to Progress in Mind in your country