Migraines happen because the brain in some people is extra sensitive and its pain and sensory systems can become over‑activated by certain internal changes and outside triggers. Genetics, hormones, and changes in brain chemicals and nerves all play a role in lowering the “migraine threshold,” so everyday things like stress, sleep changes, or bright light can suddenly tip the brain into a full migraine attack.

What a migraine is

  • Migraine is a neurological condition, not “just a bad headache,” and it often comes with nausea, light and sound sensitivity, and sometimes visual disturbances called aura.
  • During an attack, pain signals from nerves in and around brain blood vessels fire intensely, making the head feel like it’s throbbing or pulsing on one side.

What’s going wrong in the brain

  • Research suggests waves of overactive brain cells can spread across the brain and trigger changes in blood vessels and pain pathways, including the trigeminal nerve (a major facial pain pathway).
  • Important brain chemicals like serotonin and CGRP (calcitonin gene–related peptide) become imbalanced, which can widen or narrow blood vessels and amplify pain signaling.

Why some people get migraines

  • Migraines tend to run in families, and studies estimate a significant genetic contribution; many small genes together make the brain more excitable and easier to trigger.
  • Environmental and medical factors such as anxiety, depression, or bipolar disorder often occur alongside migraine, possibly due to shared brain and genetic mechanisms.

Common migraine triggers

  • Internal triggers:
    • Hormone shifts (for example around periods, pregnancy, or menopause), especially estrogen changes.
* Stress, mood changes, and sudden relaxation after stress (like the first day of vacation).

* Too little or too much sleep, fatigue, or skipping meals and low blood sugar.
  • External triggers:
    • Bright or flashing lights, loud noises, strong smells, or certain weather and barometric pressure changes.
* Foods or drinks such as alcohol (especially red wine), aged cheeses, processed foods, and too much caffeine for some people.

* Physical overexertion and, for some, specific medications like oral contraceptives or vasodilators.

Why triggers aren’t the same for everyone

  • Experts describe a personal “migraine threshold”: when brain sensitivity plus triggers crosses that threshold, an attack starts, and when it stays below, the person may feel fine.
  • Two people can be exposed to the same stress, light, or food, but only the one with a lower threshold and migraine‑prone brain chemistry will actually get a migraine.

What this means for you

  • Because the exact cause is a mix of genes, brain wiring, and lifestyle, treatment usually combines medicines with trigger management (sleep routine, stress reduction, and diet awareness).
  • Keeping a simple migraine diary (noting sleep, stress, foods, hormones, and weather) often helps people spot their biggest personal triggers and work with a clinician on prevention.

Information gathered from public forums or data available on the internet and portrayed here.