Part of the Access Doctor migraine treatment guide. Conditions overview: migraine & headache UK.
Chronic Migraine Treatment UK: When Headaches Won’t Stop
A clinically reviewed guide to chronic migraine — the IHS definition (15+ headache days/month), medication overuse headache as the most common driver, and treatment options including preventives, Botox, and CGRP inhibitors.
▶ Chronic migraine at a glance
Chronic migraine is defined as 15+ headache days per month for over 3 months. Affects around 3% of UK adults. The most common driver is medication overuse headache (MOH) — using acute medication on more than 10–15 days per month. Treatment involves addressing MOH, preventive medication, and — for refractory cases — NICE-approved botulinum toxin or CGRP inhibitors. GPhC pharmacy #9011198.
15+
Headache days per month = chronic migraine (IHS definition)
3%
UK adults have chronic migraine
MOH
Most common driver of chronification
Botox
NICE-approved for chronic migraine via specialist
Definition of Chronic Migraine
Chronic migraine is defined by the International Headache Society (IHS) as 15 or more headache days per month for more than 3 months, with at least 8 of those days having migraine features.
Episodic migraine (fewer than 15 headache days/month) can progress to chronic migraine over time — a process called chronification. Medication overuse headache (MOH) is the most common and modifiable driver of this progression.
Medication Overuse Headache (MOH) — The Most Common Cause
MOH develops when any acute headache medication is used on more than 10–15 days per month regularly. It causes a paradoxical worsening of headache frequency — a rebound effect. MOH affects approximately 1–2% of the general population and is one of the leading causes of chronic daily headache.
| Medication type | Days/month threshold for MOH risk |
|---|---|
| Triptans, ergotamines | >10 days/month |
| NSAIDs (naproxen, ibuprofen) | >15 days/month |
| Paracetamol / simple analgesics | >15 days/month |
| Opioids / combination analgesics | >10 days/month |
If you are using acute medication very frequently: Discuss this with a prescriber before stopping — abrupt withdrawal of frequent acute medication can initially worsen headache. Managed withdrawal is the treatment for MOH.
Treatment Options for Chronic Migraine
Step 1: Address medication overuse
If MOH is present, managed withdrawal from the overused medication is essential. Preventive treatment is less effective when MOH is ongoing.
Step 2: Preventive treatment
All first and second-line preventive options are appropriate — see the migraine prevention guide for detail on propranolol, topiramate, and amitriptyline.
Step 3: Specialist treatments
- Botulinum toxin A (Botox) — NICE-approved for chronic migraine (NICE TA260). 31 injection sites into head and neck muscles; administered every 12 weeks; via neurology or specialist headache service. Reduces headache days by 8–9 days/month on average.
- CGRP monoclonal antibodies (erenumab/Aimovig, fremanezumab/Ajovy, galcanezumab/Emgality) — monthly or quarterly subcutaneous injections; via specialist following failure of 3 preventives; approved for both episodic and chronic migraine.
Assess Your Headache Frequency Online
If you have 15+ headache days per month, a clinical assessment can identify whether preventive treatment is appropriate. GPhC pharmacy #9011198.
Assess My Migraines →Frequently Asked Questions
How many headache days per month is chronic migraine?
Chronic migraine is defined as 15 or more headache days per month for more than 3 months, with at least 8 of those days having migraine features. Fewer than 15 headache days per month is classified as episodic migraine.
What causes episodic migraine to become chronic?
The most common cause is medication overuse headache (MOH). Using any acute headache medication on more than 10–15 days per month regularly causes a rebound effect that progressively worsens headache frequency. Other contributing factors include anxiety, depression, sleep disorder, and obesity.
Is Botox available on the NHS for migraine?
Botulinum toxin A is NICE-approved for chronic migraine on the NHS (NICE TA260). It is administered by specialist headache services or neurology departments. Eligibility typically requires failure of 3 preventive medications and a confirmed diagnosis of chronic migraine.
Can chronic migraine be cured?
Chronic migraine can go into remission — many patients revert to episodic migraine with appropriate management. Addressing MOH, optimising preventive treatment, and identifying lifestyle triggers all contribute. Complete elimination of attacks is not always achievable, but significant frequency reduction is the realistic goal.
How do I know if I have medication overuse headache?
If you are using any acute headache medication on more than 10–15 days per month and your headaches are getting more frequent rather than better controlled, MOH is likely. The headaches of MOH are often daily or near-daily, worse in the morning, and temporarily improve with medication before rebounding.
References
- NICE. Headaches in over 12s: diagnosis and management. CG150.
- NICE. Botulinum toxin for the prevention of headaches in adults with chronic migraine. TA260.
- NHS. Migraine. nhs.uk/conditions/migraine
- BASH. Guidelines for migraine. 4th ed. 2010.
Medical disclaimer: This article is for informational purposes only. Prescription migraine treatments require a clinical consultation. Always consult a qualified healthcare professional. In a medical emergency, call 999.