A migraine can feel like much more than “just a bad headache.” Throbbing pain, nausea, sensitivity to light or sound, visual disturbances and difficulty concentrating can make an attack feel overwhelming.
But what is actually happening inside the brain during a migraine?
For many years, migraine was mainly explained as a problem involving blood vessels. Modern research has shown that the reality is much more complex. Migraine is a neurological disorder involving communication between the brain, nerves, blood vessels and pain-processing pathways. One of the most important systems involved is called the trigeminovascular system, along with signaling molecules such as calcitonin gene-related peptide (CGRP).
Let’s break down what may happen during a migraine attack in simple terms.
1. The Brain Becomes More Sensitive
A migraine doesn’t necessarily begin with pain.
Before the headache develops, changes can occur in how certain areas of the brain process sensory information. Researchers believe that people with migraine can have an altered sensitivity or excitability of the nervous system, which may make the brain more responsive to stimuli such as light, sound, smells, stress or changes in sleep.
This helps explain why something that normally feels harmless—such as a bright screen or a loud room—can become extremely uncomfortable during an attack.
Think of it as a volume control that has been turned up too high. Ordinary signals can suddenly feel much stronger than usual.
2. Some People Experience an “Aura”
Not everyone with migraine experiences aura.
For people who do, neurological symptoms can appear before or during the headache. These may include:
- Flashing lights or zigzag patterns
- Blind spots
- Tingling or numbness
- Difficulty speaking
- Temporary changes in vision
One explanation for migraine aura involves a phenomenon known as cortical spreading depression. It is a wave of changing electrical activity that moves across the outer layer of the brain, called the cerebral cortex.
This doesn’t mean that brain cells are being permanently damaged. Rather, it represents a temporary change in neuronal activity that can be associated with the neurological symptoms of aura.
3. The Trigeminal Nerve Gets Involved
One of the most important players in migraine is the trigeminal nerve.
The trigeminal nerve is a major sensory nerve that carries information from the face, head and areas surrounding the brain. Its branches also connect with pain-sensitive structures around the brain, including the meninges—the protective layers surrounding the brain.
During a migraine attack, this system can become activated.
The result is a cascade of signals that eventually reaches areas of the nervous system responsible for processing pain.
This is one reason migraine pain can be felt around the forehead, temples, eyes or other parts of the head.
4. CGRP Helps Amplify the Pain Signals
You’ve probably heard of CGRP if you’ve read about modern migraine research.
CGRP stands for calcitonin gene-related peptide. It is a signaling molecule involved in the transmission and amplification of pain within the trigeminal system. Research has found that CGRP plays an important role in migraine biology, which has also led to treatments that specifically target CGRP or its receptor.
During migraine, activation of trigeminal nerve pathways can lead to CGRP release around pain-sensitive structures.
In simple terms:
Migraine trigger → trigeminal activation → CGRP and other signaling changes → increased pain signaling → migraine symptoms
CGRP is therefore not simply a “pain chemical.” It is part of a much larger network involved in how migraine pain develops and becomes amplified.
5. Why Does the Pain Become Throbbing?
Migraine pain is often described as pulsating or throbbing.
For a long time, migraine was primarily considered a vascular disorder in which changes in blood vessels were thought to directly cause the pain. Current understanding has moved beyond that simple explanation.
Changes in blood vessels can be involved, but migraine is fundamentally a complex neurological process involving nerves, brain signaling and the trigeminovascular system.
This is why it is more accurate to think of migraine as a disorder of the nervous system rather than simply a problem with blood vessels.
6. Why Do Light and Sound Suddenly Feel Unbearable?
One of the most frustrating parts of migraine can be sensitivity to light and sound.
During an attack, the brain’s sensory-processing networks can become unusually responsive. Research continues to investigate exactly how visual, auditory and pain pathways interact during migraine.
This can make:
- Phone screens feel painfully bright
- Normal conversations seem excessively loud
- Strong smells become difficult to tolerate
- Busy environments feel overwhelming
These symptoms are real neurological symptoms, not simply a reaction to having a headache.
7. Why Can Migraine Cause Nausea?
Migraine can affect more than pain-processing pathways.
During an attack, several interconnected areas and networks of the nervous system can become involved. These interactions may contribute to symptoms such as nausea and vomiting.
That’s why someone experiencing migraine may feel sick even when the primary problem seems to be in the head.
Migraine is therefore better understood as a whole nervous-system event, rather than an isolated headache.
8. Why Does Movement Sometimes Make Migraine Worse?
Have you noticed that walking, climbing stairs or even moving your head can make migraine pain worse?
During an attack, the pain-processing system can become sensitized. As sensitivity increases, ordinary physical activity or sensory stimulation can intensify the perceived pain.
This is one reason many people instinctively want to lie down in a quiet, dark room during a migraine.
The brain isn’t simply “imagining” that movement hurts more—the pain-processing pathways can genuinely become more sensitive during an attack.
9. What Happens When the Migraine Starts to Settle?
A migraine attack eventually begins to resolve, although the process can take hours or, in some cases, longer.
As the activity of the migraine-related pathways settles, the intensity of pain and other symptoms can gradually decrease. Research has observed that CGRP levels can rise during migraine attacks and return toward normal as the attack resolves.
However, some people experience a postdrome after the main headache disappears.
They may feel:
- Tired
- Drained
- Mentally foggy
- Less focused
- Sensitive to stimulation
So, for some people, the end of the headache doesn’t immediately mean they feel completely normal again.
The Migraine Process in Simple Terms
You can think about a migraine attack as a chain of events:
Possible trigger or internal change
↓
Brain and nervous system become more sensitive
↓
Neurological symptoms may occur in some people
↓
Trigeminal pain pathways become activated
↓
CGRP and other signaling molecules become involved
↓
Pain-processing pathways become more sensitive
↓
Headache + nausea + light/sound sensitivity and other symptoms
↓
The nervous system gradually settles
↓
Recovery/postdrome
The exact sequence isn’t identical for everyone, and migraine biology is still an active area of research.
What Can Trigger This Process?
Migraine triggers vary considerably from person to person.
Commonly reported triggers include:
- Irregular sleep
- Stress or changes in stress levels
- Skipping meals
- Dehydration
- Bright or flickering light
- Strong smells
- Hormonal changes
- Alcohol
- Certain foods
- Changes in weather
- Excessive or insufficient caffeine
A trigger doesn’t necessarily “cause” migraine by itself. Instead, it may contribute to an attack in someone whose nervous system is already susceptible to migraine.
Keeping a migraine diary can help identify patterns between your daily routine and attacks.
Can Understanding the Brain Help With Migraine Management?
Yes.
Understanding migraine as a neurological condition has changed how researchers approach treatment. Modern migraine therapies can target different parts of the migraine pathway, including the trigeminal system and CGRP signaling.
Alongside appropriate medical treatment, many people benefit from maintaining consistent habits such as:
- Regular sleep
- Adequate hydration
- Regular meals
- Managing stress
- Identifying personal triggers
- Limiting known environmental triggers
- Following an individualized treatment plan
If migraines are frequent, severe, suddenly different from usual, or interfering with daily life, it’s important to discuss them with a qualified healthcare professional.
Final Thoughts
A migraine is far more complicated than an ordinary headache.
Inside the body, multiple parts of the nervous system communicate during an attack. The brain’s sensory networks can become more sensitive, the trigeminal pain pathway can become activated, and molecules such as CGRP can contribute to the amplification of pain signals.
The good news is that our understanding of migraine has advanced considerably. Scientists now have a clearer picture of the pathways involved, which has opened the door to more targeted approaches to migraine management.
Migraine isn’t “just a headache”—it’s a complex neurological event. Understanding what happens inside the brain is an important step toward understanding migraine itself.
Medical Disclaimer
This article is intended for general educational purposes and is not a substitute for diagnosis or medical advice. Migraine symptoms can vary from person to person. Consult a qualified healthcare professional for persistent, severe, or unusual headaches.
