Chronic headaches: what the pattern means

A chronic headache is a pattern of headache on many days, not one bad afternoon. For adults, the International Classification of Headache Disorders, 3rd edition (ICHD-3), uses that idea in two diagnoses this page covers. Chronic migraine is headache on 15 or more days a month for more than 3 months, with migraine features on at least 8 of those days. Chronic tension-type headache also requires headache on 15 or more days a month. The two are not the same pain.

This page is about adults. A child's headache needs a pediatric clinician. The pages that rank for "chronic headaches" include a children's hospital, and this page is not that guide.

What counts as a chronic headache?

ICHD-3 does not use one diagnosis called "chronic headache." It uses named disorders. Two of them share a frequency line.

Chronic migraine, on the ICHD-3 page read October 13, 2026, is described as headache on 15 or more days a month for more than 3 months, which on at least 8 days a month has the features of migraine. The diagnostic criteria say the person has already had migraine attacks, and that on at least 8 days a month for more than 3 months the headache meets migraine criteria, or was believed to be migraine at the start and was relieved by a triptan or ergot. It is not better accounted for by another ICHD-3 diagnosis.

The same page says the reason for a separate chronic migraine diagnosis is that the individual attacks can be impossible to separate when headache is that frequent. The pain can change from day to day, and even within one day. Both migraine-like and tension-type-like days count. Secondary headaches, which means headache from another condition, do not count toward that total.

Chronic tension-type headache, on the ICHD-3 page read the same day, is a disorder that evolves from frequent episodic tension-type headache. The episodes are daily or very frequent, typically on both sides, pressing or tightening, mild or moderate, lasting hours to days, or unremitting. The pain does not worsen with routine physical activity. It may come with mild nausea, or with light sensitivity or sound sensitivity. The notes on that page say both chronic tension-type headache and chronic migraine require headache on 15 or more days a month. For chronic tension-type headache, the headache must meet the tension-type criteria on at least 15 days. For chronic migraine, migraine features are required on at least 8 days.

People also say "chronic daily headache." That phrase is not the diagnosis name on these two ICHD-3 pages. The frequency those pages use is 15 or more days a month, which is most days, not necessarily every day.

How is chronic migraine different from a headache that comes and goes?

Episodic migraine comes in attacks, with stretches of days that are free of headache. Chronic migraine, in the ICHD-3 description, is headache on 15 or more days a month for more than 3 months, and the separate attacks blur together. The classification still requires a history of migraine, and migraine features on at least 8 days a month. A person can have many headache days and still not meet chronic migraine if those days do not have migraine features and the person has not had migraine.

Tension-type pain is the other common pattern: pressing or tightening, mild or moderate, not worse with ordinary activity. When that pattern is present on at least 15 days a month, the classification uses chronic tension-type headache, not chronic migraine.

Sorting those days is the point of a diary, below. It is not something this page can do for you.

What causes chronic headaches?

ICHD-3 sorts the pattern. It does not name one cause for every adult with frequent headache. The chronic migraine page says secondary headaches are kept out of the count, which means the clinician is also looking for a separate condition that could explain the pain.

MedlinePlus, read October 13, 2026, says almost everyone has had a headache, and that headache is the most common form of pain. It names tension headache, migraine, cluster headache, and sinus headache as common types. This page does not use MedlinePlus for the cause of a chronic pattern, because the classification above is more specific. A cause in one person can be migraine biology, a medicine, a separate illness, or something else. That is a clinician's job, using your history and exam.

What this page will not do is list a set of food triggers or call the pain a character flaw. The classification does not do that.

When should I get help right away for a headache?

MedlinePlus, read October 13, 2026, says not every headache needs a doctor's visit. It also says some headaches warn of a more serious disorder. Its overview page says to tell a clinician about sudden, severe headaches, and to get medical help right away for a headache after a blow to the head, or a headache with a stiff neck, fever, confusion, loss of consciousness, or pain in the eye or ear.

Its medical encyclopedia page, read the same day, adds these. Call 911 or go to an emergency room when:

• The headache comes on suddenly and is explosive or violent.
• It is the worst headache you have had, even if you get headaches often.
• You also have slurred speech, a change in vision, trouble moving your arms or legs, loss of balance, confusion, or memory loss.
• The headache gets worse over 24 hours.
• You also have a fever, stiff neck, nausea, and vomiting.
• The headache comes with a head injury.

The encyclopedia says a sudden explosive headache may be due to a ruptured blood vessel in the brain. This page does not add symptoms beyond those two MedlinePlus pages. If your headache feels different from your usual pattern, contact a clinician even if it is not on the list. The right step depends on your symptoms.

What should I write down before a headache visit?

The chronic migraine page says that characterizing frequently recurring headache generally requires a headache diary. Record pain and associated symptoms day by day for at least one month. Write which days hurt, how long, how strong, whether light or sound bothered you, whether you felt sick, and what you took.

A clinician needs that record because the days are hard to separate from memory alone. ICHD-3 says the pain can change within a single day. Reviewing a month of notes takes time in the visit. That is a description of the work, not a promise that a longer visit will find a cause.

Questions worth asking:

1. Do these days meet chronic migraine, chronic tension-type headache, or a different diagnosis?
2. Which of my medicines, if any, could be part of the pattern?
3. Do I need a scan, or is a scan not the next step for this pattern?
4. What should I do on a day that matches the MedlinePlus list above?

This page does not answer question 3 with a rule. No imaging guideline was opened for this draft, so it does not claim that scans are usually unnecessary. Ask the clinician, and ask what would change their mind.

Other pages about symptoms that are hard to pin down: Why fibromyalgia diagnosis takes so long and Why a chronic fatigue syndrome diagnosis takes years.

This page is general information for adults. It is not a diagnosis, a treatment plan, or advice for one person. Talk with a clinician who can see your diary and your history. You can read more on the patient page.