The Migraine Threshold and Why Several Small Factors Can Add Up

You slept less than usual. Lunch was late. The afternoon was stressful. None of those changes seemed particularly unusual, yet a migraine attack followed.

On another day, a similar disruption might pass without symptoms. That inconsistency can leave you wondering whether you have overlooked a trigger.

The migraine threshold concept offers one way to understand why several factors may matter together. It also helps explain why the same circumstances do not always have the same outcome. It does not mean you should have been able to prevent an attack.

What the migraine threshold means

Migraine is a neurological condition. Your susceptibility to an attack can change over time.

The threshold model describes a point at which an attack becomes more likely. Changes in sleep, meals, hydration or stress may contribute together, while hormonal changes or illness may also affect your susceptibility. [1,2]

For example, a short night of sleep might be followed by a day without an attack. Another short night might coincide with a missed meal and a demanding afternoon, followed by an attack.

The model suggests that the combination may be relevant. It does not establish that those circumstances caused that particular attack.

Your threshold can change

The threshold is not a fixed limit that stays the same every day. You may be more susceptible to an attack at some times than at others. [2]

This means that an experience you tolerated last week might accompany an attack this week. It also means that finding one possible contributing factor does not necessarily explain the whole episode.

There is no fixed number of triggers that guarantees an attack. You do not need to assign points to a disrupted night, a delayed meal or a stressful meeting.

The threshold concept is a way to think about changing susceptibility, rather than a daily calculation you are expected to make.

What research can tell us

Researchers have studied whether daily information about possible triggers can help predict migraine attacks.

A 90-day diary study analysed data from 178 adults with episodic migraine. Participants recorded information including sleep, stress, caffeine, alcohol and menstruation, along with their headache experiences. The researchers developed a model to estimate the likelihood of a new migraine day. It performed only slightly better than chance. [3]

In that study, the recorded factors were not sufficient for reliable next-day prediction. The results do not mean those factors are irrelevant, or that keeping records has no value. They show why observing an association and predicting an individual attack are different tasks.

The threshold model can help make sense of an experience without explaining or predicting every attack.

Some apparent triggers may be early symptoms

There is another reason the circumstances before head pain can be difficult to interpret: the migraine attack may already have begun.

Food cravings, neck stiffness and sensitivity to light can occur during the prodrome, an early phase of an attack that may precede the headache phase. [2,4]

For example, you might crave chocolate, eat some and develop head pain later. That sequence alone cannot show whether the chocolate contributed to the attack or whether the craving was already a symptom.

A retrospective study involving 1,010 people with migraine found overlap between reported triggers and corresponding early symptoms, including light sensitivity and food cravings. Because participants recalled their experiences, the findings could not establish the cause of individual attacks. [4]

When possible, note when symptoms began before deciding that a particular exposure was a trigger.

Choose a manageable adjustment

Understanding the threshold concept does not require you to avoid every possible contributing factor.

If meals are often delayed on busy days, having a snack available may make eating regularly easier. If your sleep schedule frequently changes, a conversation with your healthcare professional may help you identify a manageable routine.

Start with an adjustment that fits your circumstances. Work, caregiving, illness and other demands can make consistency difficult. Factors such as hormonal changes are not something you can simply remove from your day.

Everyday adjustments may support migraine care, but they do not guarantee prevention. Many people also need treatment, and attacks can occur despite careful planning. [1,2]

Record enough to support a conversation

If you want to explore the circumstances surrounding your attacks, choose one or two details that seem relevant to your experience.

You might note whether your sleep changed, whether a meal was delayed, or whether stress was different from usual. Record when symptoms began too.

When manageable, brief notes on days without attacks can provide context. Notice whether the same change occurred on those days and what else was different. A single comparison cannot establish a cause, but it may help you describe your experience more clearly.

Migraine Buddy can help you keep your attack records together. You could bring a question such as:

“Several attacks followed disrupted sleep and delayed meals. Could we review those circumstances alongside my treatment plan?”

Your records cannot measure your threshold or prove which factor caused an attack. They can support a more specific conversation about your symptoms, daily circumstances and care.

If no clear trigger emerges, the frequency and impact of your attacks are still useful information to discuss. You do not need to identify a cause before asking for support.

This article provides general educational information and does not replace advice from a qualified healthcare professional.

References

[1] American Migraine Foundation. Migraine Attacks Are Not Random: Understanding the Threshold Concept. May 14, 2026.
https://americanmigrainefoundation.org/resource-library/migraine-attacks-are-not-random-understanding-the-threshold-concept/

[2] The Migraine Trust. Migraine attack triggers.
https://migrainetrust.org/live-with-migraine/self-management/common-triggers/

[3] Development and Internal Validation of a Multivariable Prediction Model for Individual Episodic Migraine Attacks Based on Daily Trigger Exposures. Headache. 2020;60(10):2364–2379.
https://pubmed.ncbi.nlm.nih.gov/33022773/

[4] Schulte LH, Jürgens TP, May A. Photo-, osmo- and phonophobia in the premonitory phase of migraine: mistaking symptoms for triggers? The Journal of Headache and Pain. 2015;16:14.
https://doi.org/10.1186/s10194-015-0495-7