Is migraine a chronic condition? When doctors call it chronic migraine and how to count your days

Migraine comes back in attacks, so many people call it chronic. In the classification ICHD-3, "chronic migraine" means something narrower: headache on at least 15 days a month for more than three months, with at least 8 of those days showing migraine features. In Sam you record migraine days in your diary, and Sam adds them up per month.

Your doctor decides whether this fits you, not a number on a website. You can provide the groundwork: a diary that keeps headache days and migraine days apart. This text shows how to count them and what to bring to the appointment.

What is the difference between chronic in daily life and chronic in the classification?

The word "chronic" has several meanings, and they get mixed up. In daily life it means long-lasting or recurring. In that sense it fits many people with migraine.

The classification is stricter. Chronic migraine is its own category, number 1.3, set apart from episodic migraine. It is much rarer. A systematic review of population studies (Natoli et al., 2010) found prevalence typically between 1.4 and 2.2 percent, with wide variation between studies.

Insurance and disability rules often use their own definition of a chronic condition. Ask your insurer or benefits office how they define it.

What does ICHD-3 ask for in chronic migraine?

The International Headache Society lists four conditions. This is text for clinicians, not a self-test.

• Headache days: headache on at least 15 days a month for more than three months. Tension-type headache counts here too.
• Migraine days: on at least 8 days a month, also for more than three months, one of three things applies. The headache has migraine features, there is an aura, or you believed it was migraine at onset and a triptan or ergot drug relieved it.
• History: you have had at least five attacks that fit migraine before.
• Exclusion: no other headache disorder explains the symptoms better.

Only your doctor can check the last two.

Here is a calculation with invented numbers. You have headache on 18 days a month, and on 6 of them it has migraine features. That reaches the 15 headache days, but not the 8 migraine days. It is an arithmetic exercise, not a classification. It shows why the criteria need two numbers.

Headache almost every day is therefore not automatically chronic migraine. Your doctor checks on which days there were migraine features and whether something else fits better. It is still a reason to talk.

How do I count headache days and migraine days?

A headache day is any day with headache, with or without migraine features. Count all of them. The American Migraine Foundation notes that many people underestimate their headache frequency by counting only severe days.

A migraine day is usually a headache day with migraine features. In ICHD-3 that means at least two of four: one-sided, pulsating, moderate or severe, worse with routine activity such as climbing stairs. It comes with nausea or vomiting, or sensitivity to both light and sound. Days with aura count too, and so do days you believed were migraine at onset if a triptan or ergot drug relieved the headache.

Which days count for the classification is your doctor's decision. You record what you experienced. Four rules help:

• Count days, not attacks. With very frequent headache, single attacks often cannot be separated, says ICHD-3.
• Count every day. If a headache lasted longer than a day, each day counts.
• Add days without headache too. On paper a dash will do. An empty box cannot be told from a forgotten entry.
• Write it down the same day. After a few weeks you will not know whether Tuesday was a migraine day.

Why does the classification need a diary?

ICHD-3 itself says that describing frequent headache generally needs a diary of pain and symptoms day by day for at least a month. Without a record every number is a guess. Try to say from memory how many headache days you had last month.

The Migraine Trust recommends keeping a diary simple: date, duration, severity, other symptoms, medicines and notes. It helps your doctor make a diagnosis, shows patterns and shows whether your medicine works.

The format matters less than the fields and sticking with it. In Sam you log each attack with start, strength, duration, aura and accompanying symptoms. For entries made today, sleep and heart rate variability from Apple Health sit next to it. Our guide to migraine triggers: sleep, stress and patterns shows what else is worth a note. If you are new to all this, start with migraine diagnosis: what now.

What about acute medication and the MIDAS score?

Your diary also holds a number on medicines: on how many days a month did you take an acute medicine? You only count. ICHD-3 says the most common cause of symptoms that look like chronic migraine is medication overuse, and that around half of such patients return to an episodic pattern after drug withdrawal. The NHS advises not taking painkillers on more than 2 days a week. What your number means, and whether to change anything, you discuss with your treatment team.

Sam does not count these days. If you like, write the acute medication in the free-text note or keep a tally on paper, and your doctor assesses the number.

The MIDAS questionnaire counts a third kind of day. It asks on how many days in the last three months headache limited you at work or school, at home, and in family or leisure. Five day counts give a score and a grade from I to IV. The MIDAS migraine score tool takes about two minutes. MIDAS measures the effect on daily life, not a classification, so the score does not say whether you have chronic migraine.

What do I bring to the appointment?

If your migraine seems to be getting worse, bring numbers instead of impressions:

• The numbers for the last three months, month by month: headache days, days with migraine features, days with acute medication.
• How long attacks usually last: under four hours, up to a day or several days.
• Your MIDAS result with its date.
• The diary itself, printed or on your phone, for example the doctor report from Sam as a PDF.

Three months, because the classification looks at a period of more than three months. Ask your doctor which period they want to see.

Two questions help at the end: "How do you classify my course?" and "What should I record until the next appointment?" For a general list, see our checklist for a doctor visit with a chronic condition.

If the numbers rise over several months, talk to your doctor before the next routine visit. That holds even if you do not reach the thresholds of the classification.

Sudden weakness on one side, slurred speech or vision loss are stroke signs for the NHS, and so is a sudden, extremely painful headache. Use your local emergency number (112 in the EU, 999 in the UK, 911 in the US), even if you know migraine with aura. You do not have to work out whether it is an aura or something else. A diary does not replace an emergency call.

Count migraine days in Sam and take them to your appointment

You arrive with counted days instead of impressions, as a PDF.

• Instead of a paper headache calendar: you log each attack with start, strength, duration, aura and accompanying symptoms, and Sam counts your migraine days per month.
• Instead of counting from memory: the doctor report lists your migraine days, per month and in total, for 1, 3, 6 or 12 months or your whole record.
• Instead of Apple Health alone: for entries made today, sleep and HRV sit next to your attack. Once a month the MIDAS questionnaire adds a short check-in.

In the migraine program Sam counts only what you enter. Headache without migraine features belongs in the symptom diary, and whether you have chronic migraine is for your treatment team.

Try Sam Health

Sam is a wellness companion, not a medical device. The app does not diagnose, treat, cure or prevent any condition or health state. Always consult qualified professionals for medical decisions.

Sources

Updated: October 2026

• International Headache Society: ICHD-3, 1.3 Chronic migraine and 1.1 Migraine without aura
• American Migraine Foundation: What is chronic migraine?
• The Migraine Trust: Keeping a headache diary
• NHS: Migraine treatment (page last reviewed 10 March 2026) and Stroke symptoms
• Natoli JL et al.: Global prevalence of chronic migraine: a systematic review. Cephalalgia 2010;30(5):599-609, PubMed 19614702
• Stewart WF et al.: Development and testing of the Migraine Disability Assessment (MIDAS) Questionnaire to assess headache-related disability. Neurology 2001;56(Suppl 1):S20-S28, PubMed 11294956