Postdrome is the recovery phase after a migraine attack ends — typically 24 to 48 hours of fatigue, brain fog, mood flatness, neck stiffness, and reduced cognitive performance. It’s distinct from the headache itself but often as disabling. About 80 percent of people with migraine report at least some postdromal symptoms; in many it’s the longest single phase of the attack cycle.

The colloquial name is “migraine hangover” — apt because the subjective experience overlaps significantly with the recovery from heavy alcohol use (without the regret of choice).

The most common postdromal symptoms

  • Fatigue or exhaustion — out of proportion to physical activity. The single most common postdromal feature.
  • Cognitive sluggishness — brain fog, slowed thinking, word-finding difficulty, difficulty concentrating.
  • Mood flatness — depression, irritability, or sometimes a brief euphoria.
  • Residual neck pain or muscle soreness — particularly in the back of the head and neck.
  • Mild head heaviness — not full headache, but a dull awareness the head was just hurting.
  • Light or sound sensitivity — diminished from the attack itself but still present.
  • Difficulty sleeping despite fatigue — the opposite of what you’d expect.

The cluster varies between individuals, much like the prodrome cluster does. A person’s postdromal pattern tends to be consistent attack-to-attack.

Why postdrome happens

The biology is incompletely understood, but the leading hypotheses involve:

  • Neurotransmitter depletion — serotonin and other transmitters released during the attack take time to replenish.
  • Residual inflammation — the trigeminovascular activation that drove the headache leaves a lingering inflammatory signal.
  • Energetic cost — the cortex effectively burns substantial energy during an attack; recovery is biologically real.
  • Medication effects — some abortive medications produce their own brief sedation or cognitive effects that compound the postdromal phase.

These are mechanistic explanations rather than fully validated pathways — postdrome is a less-studied phase than prodrome or the attack itself.

What postdrome is NOT

A few common confusions worth clearing:

  • Not a “weak migraine” — postdrome can occur without head pain (after an aura without headache) but it’s a distinct phase, not an attenuated attack.
  • Not just fatigue from sleeping poorly during the attack — postdromal fatigue persists even when sleep was relatively preserved.
  • Not “you’re just being dramatic” — for some people, the postdrome is more disabling than the headache itself. Reported productivity drops during postdrome can match or exceed those during the headache phase.

Acting during postdrome

There is no specific abortive or “rescue” treatment for postdrome. Supportive practice includes:

  • Rest where possible — pushing through a postdrome typically prolongs it.
  • Hydration — though the evidence is modest, no harm.
  • Gentle activity when energy returns — light walking, stretching. Vigorous exercise can re-trigger in some people.
  • Avoiding new trigger exposures during recovery — the threshold for the next attack may be lower while the system is recovering.

Avoid the impulse to “catch up” on missed work the moment the headache ends. Many people self-report that the next attack follows shortly after they push through a postdrome.

What Hermly observes during postdrome

Hermly tracks attack end times (via the user ending Attack Mode or the auto-end after 24 hours) but does not have a separate “postdrome” mode. After an attack ends, the user returns to the normal Today flow.

What Hermly’s model does capture: the hadHeadacheLast36h feature stays positive through the typical postdromal window, which (correctly) keeps the recent-attack signal contributing to the next day’s risk. This reflects the real-world cluster pattern — attacks often come in groups, and the post-attack window is a higher-risk one.

If your postdrome is consistently long (>48 hours) or particularly disabling, that’s information worth bringing to your doctor. Hermly’s monthly report includes attack durations and inter-attack intervals; the postdrome itself isn’t a separately logged event in the current version.