Chronic migraine hides your triggers under a noisy between-attack baseline
Trigger diaries assume you felt fine before the exposure. With chronic migraine, the days between attacks are rarely clean, and the correlations built on them aren't either.
The Friday your trigger diary never recorded
Every trigger diary rests on one quiet assumption: that you felt normal before the thing you're testing. Red wine Friday, attack Saturday. The math needs a Friday that was clean.
For a lot of people with chronic migraine, Friday was already a three out of ten. The fluorescent light at work was too sharp by noon. The fog came in mid-afternoon, same as Thursday, same as Wednesday, and the neck never quite loosened after Monday's attack. Then the wine. Then Saturday.
The app files it under wine.
Maybe it was. Or maybe Saturday's attack was already coming, and the wine happened to be the last thing logged before it. The diary has no way to know, because it never asked what Friday felt like before the glass. That missing Friday is the whole problem.
The noisy floor
We call it the noisy floor.
Trigger tracking is signal detection, and signal detection needs a quiet background. Episodic migraine often supplies one: an attack, a recovery, several days near baseline, another attack. Against that floor, an exposure that keeps showing up before attacks stands out.
Chronic migraine takes the floor away. ICHD-3 defines it as headache on 15 or more days a month for more than three months, with migraine features on at least 8 of those days. At that density the stretches between attacks are short, and they're rarely empty. Interictal days (the ones between attacks) can carry their own fatigue, light sensitivity, neck stiffness and cognitive slowdown. Headache researchers treat this between-attack load as a burden worth measuring on its own terms Buse et al. published the Migraine Interictal Burden Scale (MIBS) on January 1, 2007 ([source](https://www.researchgate.net/publication/284698878_Development_and_validation_of_the_Migraine_Interictal_Burden_Scale_MIBS_A_self-administered_instrument_for_measuring_the_burden_of_migraine_between_attacks)).
So every candidate trigger lands on top of symptoms that were already running. A correlation engine fed that data will still find patterns. It just can't tell you whether they're real.
15+
headache days per month to meet the chronic migraine definitionICHD-3, 2018
8+
of those days with migraine featuresICHD-3, 2018
3+ months
the pattern must persistICHD-3, 2018
Why logging harder doesn't fix it
When a trigger diary comes up empty, the advice circles back to the person holding it. Log every day. Add more detail. Give it three months. The implied diagnosis is discipline.
The actual diagnosis is structure. Most trigger logs are event-shaped: the attack is a record with a start and an end, and each candidate trigger is a separate exposure with a timestamp. Nothing in that shape stores the state you were in when the exposure happened. A flawless logger with chronic migraine still produces a dataset with the most important variable left out, and more entries of the same shape only make the wrong answer look more confident.
People living with this have noticed. On r/bulletjournal, migraine spreads built around daily symptom grids get shared as workarounds for apps that only want to hear about attacks. That's patients rebuilding the missing column by hand.
Postdrome is how the floor gets raised
Look at where the elevated floor comes from and postdrome keeps showing up.
The attack phases aren't sealed off from each other. Prospective diary research on postdrome found that non-headache symptoms after the pain resolves are common, with tiredness, cognitive difficulty and neck stiffness among the ones people report most. Prodrome symptoms, meanwhile, can start well before head pain begins.
At episodic frequency those phases sit at the edges of a long quiet stretch. At chronic frequency they collide. The postdrome from Monday's attack is still fading when the prodrome of Thursday's begins, and the days in between never reach zero. That overlap is the noisy floor, built from the attack cycle itself.
Most trackers close the entry when the headache stops, which means the phase that raises tomorrow's baseline is the one they don't record.
Usually nothing, or an exposure mistaken for a cause
Headache
Head pain, light and sound sensitivity, nausea
The full record
Postdrome
Tiredness, brain fog, residual head pain, neck stiffness
Usually nothing once pain ends
Interictal
Varies; can include fatigue and light sensitivity
Usually nothing
Symptom examples from ICHD-3 descriptions and published migraine-phase research. The right column is our category-level observation of attack-first tracking apps.
One week, logged two ways
Take an illustrative week, a composite rather than any one patient's record.
Monday: an attack, treated. Tuesday: no head pain, but heavy fog and a stiff neck. Wednesday: the fog lifts some, and light sensitivity sits at a low hum. Thursday: short sleep. Friday: a late coffee and a glass of wine at dinner. Saturday: attack.
An attack-first log holds two entries and a handful of exposures. It proposes coffee and wine, and after a month of similar weeks it'll probably say so with conviction.
A continuous log holds the same exposures plus a daily floor rating and the postdrome carried until it cleared. It shows that Monday's after-phase never fully resolved, that the floor sat above zero every day, and that Friday started already elevated. Across a month, that record can ask a better question: do attacks follow the exposures, or the floor? If most attacks land on already-high days whether or not wine was involved, wine was probably a bystander. If wine attacks cluster on low-floor days too, it deserves a closer look.
Neither answer is visible without the floor.
What to track if the floor is the variable
If the floor is the variable, trigger tracking gets reordered around it.
Rate the day, every day, including the ones with no attack. A single 0 to 10 number is enough. Keep logging after the headache stops, and close the entry when the fog and fatigue clear. Compare exposures only against days that started from a similar floor.
And bring the floor to appointments. Preventive treatment is usually judged by monthly migraine days, but a floor that drops from four to one is a change you'd feel even if the day count barely moved. Your neurologist can't see that unless it's written down.
For chronic migraine, the most useful record is the one kept between attacks.
Medication days raise the floor too
ICHD-3 describes medication-overuse headache with regular acute medication use on 10 or more days a month for triptans (15 or more for simple analgesics) over more than three months. If your acute-treatment days are near those numbers, log them alongside your daily floor and raise it with your clinician. A sudden change in your usual pattern, a new worst-ever headache, or new neurological symptoms need prompt medical attention.
Where Postdrome fits
We built Postdrome because of migraines in our lives, and because every attack-only app we tried left out the days that mattered most for chronic migraine.
The timeline stores a daily floor rating alongside attacks, and it treats postdrome as its own phase that stays open until you say it's done. When you can barely look at a screen, Aura Mode keeps logging to a few low-contrast taps. Your data stays on your device and exports cleanly when you want to hand it to a neurologist or move it somewhere else. Pricing is a one-time lifetime purchase, stated up front.
None of that finds your triggers for you. It gives the floor a column, which is what a trigger diary needed from the start.
Start logging your baseline, not just your attacks
Postdrome records a daily baseline and keeps postdrome open as its own phase, so the days between chronic migraine attacks finally show up in your record. Everything stays on your device, exports for your neurologist, and costs a single lifetime price with no subscription.
