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How to diagnose

Headache, including migraine, is one of the top 10 reasons for visiting a GP, with consultation rates in the UK of 6.4 per 100 female adult patients per year and 2.5 per 100 male adult patients.5 25% of new referrals to neurologists are for headache.6

It can be challenging to accurately diagnose patients with chronic migraine.7 In one study of 512 patients who met the criteria for chronic migraine and were consulting a healthcare professional, only 24.6% had received an accurate diagnosis.7 The first diagnostic step is to distinguish a primary headache from a secondary headache; secondary headaches can be indicated by ‘red flag’ symptoms and will likely require specific tests for confirmation of diagnosis.8

Having excluded secondary headaches, the next step is to diagnose a specific primary headache syndrome, based on frequency and duration of headache.8-10

Three steps to making a chronic migraine diagnosis9,10

Adapted from  International Headache Society, 20189 and Lipton R B et al, 201110

Tutorial video: accurate diagnosis of chronic migraine

Listen to Dr Andrew Blumenfeld, Director of the Headache Center of Southern California, US, discuss the unmet need for better diagnosis in chronic migraine, differential diagnoses and chronic daily headache classification.

Risk factors for developing chronic migraine

Chronic migraine often develops from episodic migraine after a period of increasing headache frequency. This higher frequency is associated with a number of risk factors, including:10,11

  • age
  • sex (female)
  • obesity
  • snoring
  • head injury
  • stressful life events
  • depression and/or anxiety
  • cutaneous allodynia
  • overuse of opioids
  • overuse of barbiturates
  • high caffeine intake
  • ineffective acute headache treatment

Chronic migraine is a complex neurological disease requiring appropriate effective management - including treatment or referrals to improve patient outcomes2,9,12

CM: chronic migraine.

BOTOX® (botulinum toxin type A) is indicated for the prophylaxis of headaches in adults with chronic migraine (headaches on at least 15 days per month of which at least 8 days are with migraine).13

Red flag signs/symptoms for secondary headache8,14

AVM: arteriovenous malformation.
Adapted from Bigal M E et al, 20078

In all cases, neuroimaging may assist diagnosis. Other possible investigations include lumbar puncture, collagen vascular evaluation, biopsy and blood tests.8

References: 8. Bigal M E et al. J Headache Pain 2007;8:263-272; 14. Dodick D W. Adv Stud Med 2003;3:S550-S555



  1. Allergan. Data on file. INT/0423/2016
  2. Aurora S K, Winner P et al. OnabotulinumtoxinA for treatment of chronic migraine: pooled analyses of the 56-week PREEMPT clinical program. Headache 2011;51(9):1358-1373
  3. Blumenfeld A M, Stark R J et al. Long-term study of the efficacy and safety of OnabotulinumtoxinA for the prevention of chronic migraine: COMPEL study. J Headache Pain 2018;19(1):13
  4. Allergan. Data on file. 014
  5. Latinovic R, Gulliford M, Ridsdale L. Headache and migraine in primary care: consultation, prescription, and referral rates in a large population. J Neurol Neurosurg Psychiatry 2006;77(3):385-387
  6. Buture A, Ahmed F et al. Perceptions, experiences, and understandings of cluster headache among GPs and neurologists: a qualitative study. Br J Gen Pract 2020;70(696):e514-e522
  7. Dodick D W, Loder E W et al. Assessing barriers to chronic migraine consultation, diagnosis, and treatment: results from the Chronic Migraine Epidemiology and Outcomes (CaMEO) study. Headache 2016;56(5):821-834
  8. Bigal M E, Lipton R B. The differential diagnosis of chronic daily headaches: an algorithm-based approach. J Headache Pain 2007;8(5):263-272
  9. International Headache Society (IHS). International classification of headache disorders (3rd edition) guidelines. Available at: Accessed April 2022
  10. Lipton R B. Chronic migraine, classification, differential diagnosis, and epidemiology. Headache 2011;51 Suppl 2:77-83
  11. May A, Schulte L H. Chronic migraine: risk factors, mechanisms and treatment. Nat Rev Neurol 2016;12(8):455-464
  12. Weatherall M W. The diagnosis and treatment of chronic migraine. Ther Adv Chronic Dis 2015;6(3):115-123
  13. BOTOX® Summary of Product Characteristics. Available at: Accessed April 2022
  14. Dodick D W. Clinical clues and clinical rules: primary vs secondary headache. Adv Stud Med 2003;3(6C):S550-S555

Please refer to the BOTOX® Summary of Product Characteristics for further information on adverse events, contraindications and special warnings and precautions for use.


Adverse events should be reported. Reporting forms and information can be found at

Adverse events should also be reported to AbbVie on [email protected] 


Date of preparation: April 2022. UK-BCM-220061.