How long do migraines last? The ICHD-3 window

Short answer: ICHD-3 defines an untreated or unsuccessfully treated migraine attack as 4 to 72 hours. Most attacks fall in the 12–24 hour range. Anything reliably beyond 72 hours is classified as status migrainosus and is considered a medical condition that warrants urgent treatment rather than waiting out.

This page covers the typical duration variation, what the four phases add to total disability time, and when a long migraine crosses into “this needs medical attention now” territory.

The 4–72 hour ICHD-3 window

The 4 hour floor and 72 hour ceiling are part of the formal ICHD-3 1.1 criteria for migraine without aura (criterion B). Attacks shorter than 4 hours are classified differently — typically as probable migraine if the rest of the criteria are met, or as a different headache type entirely.

The 72-hour ceiling is the threshold that distinguishes a typical migraine from status migrainosus, which is treated as a clinical emergency. The threshold isn’t arbitrary — beyond 72 hours, the risk of complications (medication overuse, dehydration, secondary triggers) rises significantly, and breaking the cycle with stronger interventions (IV medications, corticosteroids) is often required.

Typical duration distribution

In population cohort studies, migraine duration falls roughly:

• < 4 hours: ~10% (often successfully aborted or probable migraine)
• 4–12 hours: ~25%
• 12–24 hours: ~35% (the modal case)
• 24–48 hours: ~20%
• 48–72 hours: ~7%
• > 72 hours (status migrainosus): ~3%

A given person’s pattern tends to be consistent. If your typical attack is 8 hours, you’re unlikely to have many that last 36 hours. If yours run 24–36 hours regularly, that’s the personal norm.

What makes some attacks longer

Several factors are reliably associated with longer attacks:

• Late treatment — taking acute medication after the headache is established (with allodynia present) reduces effectiveness and lengthens the attack.
• Untreated entirely — running an attack to natural resolution typically takes longer than treating it.
• Hormonal triggers — menstrual migraine attacks tend to be longer than other-cause attacks in the same person.
• High pain attacks — severe attacks tend to last longer than mild ones in the same person.
• Stress + sleep deprivation at the time of onset — depleted baseline resources lengthen recovery.
• Status migrainosus history — having had one increases the risk of future prolonged attacks.

The total disability time is longer than the headache

Most people think of “migraine duration” as the headache phase. Clinically, the disability runs through all four phases:

• Prodrome (2–48 hours before pain) — functional but diminished, mood/cognitive symptoms.
• Aura (if present, 5–60 minutes) — typically disabling for the duration.
• Headache (4–72 hours) — the canonical phase.
• Postdrome (24–48 hours) — fatigue, brain fog, mood flatness. Often as disabling as the headache itself for some people.

A “24-hour migraine” with a 24-hour postdrome and 12 hours of recognisable prodrome adds up to 60 hours of altered function — the headache being roughly 40% of the total.

This is part of why migraine MIDAS scores (disability assessments) often surprise patients. The headache is the salient memory; the surrounding hours are part of the same disability.

When duration becomes status migrainosus

ICHD-3 1.4.1 defines status migrainosus as a migraine attack lasting more than 72 hours with continuous severe pain. Brief pain-free intervals (< 12 hours due to sleep or medication) don’t reset the clock.

Why it matters: status migrainosus carries higher risk of:

• Medication overuse during the attempt to self-manage.
• Dehydration from prolonged nausea and reduced intake.
• Secondary trigger cascade as recovery takes longer.
• Stroke in rare cases (especially with prolonged aura).

The standard approach: don’t try to wait it out. Urgent care, ED, or your headache specialist can administer IV medications (typically IV NSAIDs + antiemetics, sometimes corticosteroids, occasionally IV dihydroergotamine) that interrupt the cycle.

Red flags that need urgent evaluation

Beyond simple long duration, these features warrant immediate medical attention:

• Sudden severe headache reaching peak in under a minute.
• New-pattern headache after age 50.
• Headache with fever, stiff neck, rash, or new neurological deficit.
• Headache after head trauma.
• “Worst headache of your life.”

These can indicate non-migraine emergencies (subarachnoid haemorrhage, meningitis, stroke). Don’t assume a long headache is “just a long migraine” if any of these features are present.

What Hermly tracks for duration

Hermly logs the start time of every attack you record. When you end an attack (manually or via the auto-end after 24 hours), the duration is computed and contributes to your history.

Two specific patterns Hermly surfaces in the doctor report:

• Median attack duration over the rolling 90 days.
• Distribution — how many attacks fell in each duration band.

These help your clinician spot trends — e.g., attacks getting longer over months can indicate worsening pattern or treatment breakthrough that warrants regimen review.

What Hermly does not do: tell you when to seek urgent care. That decision is yours, in real-time, based on your symptoms and the red-flag features above. An app can’t do triage.