A Migraine Attack: What Really Happens Inside Your Body

If you’ve ever experienced a migraine, you know it’s far more than just a bad headache. It’s a complex neurological event that can affect your entire body. You clicked to understand what’s happening on the inside during an attack, and this guide will walk you through the science, step by step.

The Journey of a Migraine: A Four-Phase Process

A migraine isn’t a single event but rather a cascade of neurological changes that often unfold in up to four distinct phases. While not everyone experiences all four, understanding them provides a clear picture of what your brain and body are going through.

Phase 1: The Prodrome (The Subtle Warning)

Long before the intense pain begins, sometimes a day or two in advance, your body may send subtle warning signals. This is the prodrome phase, and it’s believed to originate in an area of the brain called the hypothalamus, which regulates many of your body’s automatic functions.

During this stage, you might notice:

  • Mood Swings: You could feel unusually irritable, depressed, or even euphoric for no apparent reason.
  • Food Cravings: A sudden, intense craving for specific foods, often chocolate or salty snacks, is common.
  • Neck Stiffness: A stiff or sore neck is a frequent early indicator for many people.
  • Increased Thirst and Urination: Your body’s fluid balance can be temporarily disrupted.
  • Fatigue and Yawning: Unexplained tiredness and frequent yawning can signal that a migraine is on its way.

These symptoms occur as your brain chemistry begins to change, setting the stage for the more intense phases to come.

Phase 2: The Aura (The Sensory Disturbance)

About one-third of people who experience migraines will have an aura. This phase typically lasts from 5 to 60 minutes and occurs right before the headache phase. An aura is a set of temporary neurological symptoms, most often visual.

The underlying cause of aura is a phenomenon called Cortical Spreading Depression (CSD). This is essentially a slow-moving wave of intense nerve-cell activity that sweeps across the surface of your brain (the cortex), followed by a period where the nerve cells become temporarily quiet.

Common types of aura include:

  • Visual Aura: This is the most common. You might see flashing lights, geometric shapes, zig-zag lines (fortification spectra), or experience a blind spot (scotoma) that slowly expands.
  • Sensory Aura: This involves a feeling of tingling or numbness, like pins and needles. It often starts in the fingertips of one hand and slowly travels up the arm to the face, lips, and tongue.
  • Speech or Language Aura (Aphasia): You might have trouble finding the right words or understanding what others are saying.

Phase 3: The Attack (The Headache and Beyond)

This is the most debilitating phase, characterized by the severe headache most people associate with a migraine. The pain is often throbbing or pulsing and is typically located on one side of the head. But the pain is just one part of a much larger story.

Here’s what’s happening inside your body:

  1. Trigeminal Nerve Activation: The CSD wave from the aura phase (or a similar process in migraines without aura) is thought to activate the trigeminal nerve. This is a massive nerve system with branches across your face and head, and it’s the main pathway for head pain.
  2. Release of Neuropeptides: Once activated, the trigeminal nerve releases inflammatory substances called neuropeptides into the sensitive outer covering of the brain (the meninges). The most significant of these is Calcitonin Gene-Related Peptide (CGRP).
  3. Inflammation and Vasodilation: CGRP causes the blood vessels in the meninges to swell and become inflamed. This process of inflammation and vasodilation (widening of blood vessels) sends a flood of pain signals back through the trigeminal nerve to the brain.
  4. Central Sensitization: As the attack continues, the pain-sensing neurons in your brainstem and thalamus become hypersensitive. This is called central sensitization. It amplifies the pain signals and is the reason why even normal stimuli, like light, sound, or touch, can become intensely painful.

This is why the attack phase includes so much more than just pain:

  • Nausea and Vomiting: The brain’s “vomiting center” in the brainstem can be activated.
  • Extreme Sensitivity to Light (Photophobia): Your brain is on high alert and cannot properly filter sensory information.
  • Extreme Sensitivity to Sound (Phonophobia): Similar to photophobia, sounds can feel overwhelmingly loud and painful.
  • Dizziness or Vertigo: The migraine process can affect your vestibular system, which controls balance.

Phase 4: The Postdrome (The Migraine Hangover)

After the intense pain of the attack subsides, the migraine event isn’t necessarily over. The postdrome phase can last for a day or two and is often described as a “migraine hangover.” The brain is slowly recovering from the intense neurological storm it just weathered.

During postdrome, you might feel:

  • Exhausted and Drained: Your body has used up a lot of energy.
  • Confused or “Foggy”: Difficulty concentrating is very common.
  • Sore and Tender: Some people feel muscle aches or tenderness where the headache was most intense.
  • Mild Euphoria: Conversely, some individuals report feeling unusually refreshed or happy.

This final phase highlights that a migraine is a full-body experience, with effects that linger long after the headache is gone.

Beyond the Brain: How a Migraine Affects the Whole Body

The neurological cascade of a migraine doesn’t stay confined to the head. It sends ripple effects throughout your body’s interconnected systems.

  • The Gut-Brain Axis: The constant communication between your brain and gastrointestinal system is why nausea, vomiting, and even diarrhea or constipation can accompany a migraine. The same neurotransmitters, like serotonin, that play a role in migraine also play a huge role in gut function.
  • The Autonomic Nervous System: This system controls your automatic bodily functions. During a migraine, it can go haywire, leading to symptoms like sinus congestion, a runny nose, sweating, pale skin, and fluctuations in blood pressure.

Understanding these complex internal processes helps clarify why a migraine is so much more than a headache. It’s a powerful neurological event that requires careful management, rest, and understanding.

Frequently Asked Questions

Is a migraine just a really bad headache? No. A headache is a symptom, whereas a migraine is a complex neurological disorder. A migraine attack involves a cascade of changes in the brain that cause the headache pain, along with many other symptoms like nausea, aura, and extreme sensitivity to light and sound.

What is CGRP and why is it important? CGRP stands for Calcitonin Gene-Related Peptide. It’s a protein that plays a central role in causing the pain and inflammation during a migraine attack. Its discovery has been a major breakthrough, leading to a new class of highly effective migraine-specific treatments called CGRP inhibitors (like Aimovig, Emgality, and Nurtec ODT) that work by blocking its effects.

Why does light and sound hurt so much during a migraine? This is due to a process called central sensitization. During an attack, the nerves in your brain that process sensory information become hyperexcitable. As a result, they amplify normal signals from your eyes and ears, interpreting them as painful. This is why many people need to rest in a dark, quiet room during an attack.