Chronic migraine and chronic daily headache: causes and treatment

Chronic migraine means having headache on 15 or more days a month for more than three months, with migraine features on at least 8 of those days. It is one form of chronic daily headache, the umbrella term for any headache on 15 or more days a month. If you have a headache every day, or almost every day, effective treatment is available.

What is chronic daily headache?

Chronic daily headache covers every type of headache that occurs on at least 15 days a month for at least three months in a row. This follows the definitions of the International Headache Society (ICHD-3). It is not about the occasional headache, but a pattern of persistent headache that has a major effect on daily life.

The pain can range from a pressing, tight feeling to intense, throbbing attacks. Symptoms differ from person to person.

What is the difference between chronic headache and chronic migraine?

The two are often confused, but they are not the same diagnosis. Chronic migraine is a specific type of chronic headache in which at least 8 days a month have migraine features: throbbing, often one-sided headache, nausea, and sensitivity to light and sound. About 10 million people in the UK live with migraine, and some of them develop chronic migraine.

Other types, such as chronic tension-type headache, feel different: more like pressure or a tight band around the head, without the typical migraine features. The distinction matters because treatment differs.

What causes chronic migraine?

The causes are complex and differ by type. In chronic migraine, genetics play a central role: migraine is an inherited brain condition. The trigeminovascular system, the network linking the trigeminal nerve and the blood vessels around the brain, becomes oversensitive and reacts too strongly to stimuli. CGRP (calcitonin gene-related peptide) plays a key role: it is released during an attack, widens blood vessels and activates pain nerves.

Other factors that can help headache become chronic:

• Medication overuse: taking painkillers or triptans too often (on more than 10 to 15 days a month) can lead to medication overuse headache
• Undertreatment: many people with migraine do not get the right preventive treatment, so attacks become more frequent over time
• Other conditions: sleep problems, anxiety and depression can make headache worse

Importantly, lifestyle is not the cause of migraine. Migraine is an inherited brain condition, and it is not your fault.

What types of chronic daily headache are there?

The International Headache Society (ICHD-3) describes several types:

• Chronic migraine: headache on 15 or more days a month, at least 8 with migraine features. Often one-sided and throbbing, with nausea and sensitivity to light and sound, although not everyone has all of these in every attack.
• Chronic tension-type headache: a pressing, tight pain on both sides of the head, like a band. Less intense than migraine, but it can be there every day.
• Medication overuse headache (MOH): develops when painkillers or triptans are taken too often. The headache medicine becomes part of the problem rather than the solution.
• Cluster headache: extremely severe, stabbing pain around one eye, in attacks lasting 15 minutes to 3 hours. Rarer than migraine, but one of the most painful headache types.
• Hemicrania continua: a continuous, one-sided headache that responds to the medicine indometacin.

How is chronic migraine managed?

Treatment depends on the type of headache. For chronic migraine, it usually combines preventive treatment, careful use of acute medication and regular review.

Preventive treatment

The CGRP monoclonal antibodies erenumab (Aimovig), fremanezumab (Ajovy) and galcanezumab (Emgality) were developed specifically to prevent migraine. You inject them yourself at home, usually every 4 weeks. The gepants atogepant and rimegepant are tablets that can also be used to prevent migraine attacks.

Other options exist, such as older preventive tablets or botox injections for chronic migraine. We do not offer these, but your GP can discuss them with you.

Acute medication

Alongside prevention, good acute medication remains important: triptans, or the gepants atogepant and rimegepant. Take care not to use acute medication too often, to avoid medication overuse headache. A useful rule of thumb is no more than 2 to 3 days a week.

At The Migraine Clinic, a migraine specialist draws up a personal treatment plan with you. Our clinic is specialised exclusively in migraine and works fully online, through video consultations.

When should you see a specialist?

Do you recognise yourself in frequent or persistent headache that affects your daily life? Then it is time to act, especially if:

• you have headache on more than 15 days a month
• you regularly use painkillers or triptans (more than 2 to 3 days a week)
• previous treatments have not worked well enough
• your headache is getting worse or changing in character

If your headache is new, sudden and severe, or comes with weakness, confusion, fever or a stiff neck, call 999 or go to A&E.

Can chronic migraine be treated successfully?

In many cases it can be treated effectively, so that attacks become much less frequent and less intense. Preventive medicines such as the CGRP antibodies and gepants can substantially reduce the number of migraine days.

Get started

Take the migraine test to see whether your symptoms fit migraine. You do not need a referral from your GP: you can book directly. See how to start, or read more about preventive medication and acute medication.

This article was written by the medical team of The Migraine Clinic, an online clinic specialised exclusively in migraine.