A migraine is a neurological event, not just a bad headache

A migraine is a specific type of headache caused by changes in brain chemistry and blood vessel activity, not by tension in your neck or stress alone. During a migraine, your brain's electrical activity shifts, triggering a cascade of events: blood vessels constrict and then dilate, inflammation spreads around nerves, and pain signals intensify. This is why migraines feel different from other headaches—they often come with nausea, sensitivity to light or sound, and sometimes vision changes that happen before the pain starts.

The pain itself is typically one-sided, throbbing, and moderate to severe. It can last 4 to 72 hours. What makes a migraine a migraine, rather than a regular headache, is this combination of neurological symptoms happening together, not just the intensity of the pain.

Key Takeaways

  • A migraine involves changes in brain chemistry and blood vessel function, which is why it causes symptoms beyond just head pain.
  • Many migraines include a warning phase called an aura—flashing lights, blind spots, or tingling—that can appear 20 to 60 minutes before the headache starts.
  • Migraines often come with nausea, vomiting, and extreme sensitivity to light, sound, or smell that regular headaches do not typically cause.
  • The pain usually affects one side of the head and has a throbbing quality, and it can last anywhere from a few hours to three days.

The phases of a migraine attack

A full migraine attack often unfolds in distinct phases, though not everyone experiences all of them. The prodrome phase happens hours or even a day before the headache—you might feel mood changes, cravings for certain foods, neck stiffness, or unusual energy levels. Many people recognize this phase as a warning that a migraine is coming.

The aura phase comes next for about one-third of migraine sufferers. During aura, you see visual disturbances like flashing lights, zigzag lines, or temporary blind spots in your vision. Some people experience tingling in their hands or face, or difficulty finding words. Aura typically lasts 20 to 60 minutes and then fades as the headache pain begins.

The headache phase is when the throbbing pain peaks. This is when nausea and sensitivity to light and sound are strongest. Finally, the postdrome phase happens after the pain subsides—you might feel exhausted, foggy, or emotionally drained for hours or even a day afterward.

Why migraines feel so different from regular headaches

A tension headache usually feels like pressure or tightness across both sides of your head, and you can often still function. A migraine is disabling—many people need to lie down in a dark, quiet room. The throbbing quality of migraine pain comes from the dilation of blood vessels in the brain, whereas tension headaches come from muscle tightness.

The accompanying symptoms set migraines apart most clearly. Nausea and vomiting are common with migraines but rare with tension headaches. Sensitivity to light, sound, and smell during a migraine is intense enough that normal activities become unbearable. A person with a tension headache might still work or socialize; a person in a migraine attack typically cannot.

Migraines also tend to run in families and follow patterns—they may happen on certain days of the week, around your menstrual cycle, or after specific triggers like certain foods or weather changes. Tension headaches are usually more random and tied directly to stress or muscle strain.

What triggers a migraine attack

Migraine triggers vary widely from person to person, but common ones include hormonal changes (especially in people who menstruate), skipped meals, dehydration, caffeine withdrawal, sleep disruption, and stress. Some people notice migraines after eating foods like aged cheese, processed meats, or foods containing MSG. Environmental triggers include bright lights, strong smells, loud noise, and weather changes.

Importantly, a trigger does not always cause a migraine—you might eat the same food or experience the same stress on different days with different results. This is because migraines require a combination of factors. You might be more vulnerable to a trigger when you are already sleep-deprived, stressed, or hormonal. Understanding your personal pattern takes time and often involves keeping a migraine diary.

Not all migraines have an obvious trigger. Some happen seemingly at random, which is why identifying patterns can be difficult and frustrating.

How doctors distinguish migraines from other headache types

Doctors use specific criteria to diagnose a migraine. The most widely used standard is from the International Headache Society and looks for a pattern: at least five headaches lasting 4 to 72 hours each, with pain on one side of the head, throbbing quality, moderate to severe intensity, and worsening with physical activity. The headache must also include at least one of these: nausea or vomiting, or sensitivity to both light and sound.

If you have aura symptoms, those are documented separately because migraine with aura and migraine without aura are tracked differently in medical records and can have slightly different treatment approaches. Your doctor will ask detailed questions about when your headaches started, how often they occur, what they feel like, and what happens before, during, and after.

Brain imaging like an MRI or CT scan is not routinely needed to diagnose a migraine if your symptoms fit the pattern and your neurological exam is normal. Imaging is used when your headache pattern changes suddenly, when you have new symptoms, or when the diagnosis is unclear.

The role of brain chemistry in migraines

Migraines involve an imbalance of neurotransmitters—chemical messengers in the brain. Serotonin is one of the most studied. During a migraine, serotonin levels drop, which affects blood vessel function and pain perception. This is why many migraine medications work by raising serotonin levels or mimicking its effects.

Another key player is calcitonin gene-related peptide (CGRP), a molecule that causes inflammation around nerves and blood vessels. When CGRP levels rise, blood vessels dilate and pain signals amplify. Newer migraine medications specifically block CGRP, which is why they have been effective for people who do not respond to older treatments.

The brain's electrical activity also shifts during a migraine. A wave of electrical activity called cortical spreading depression moves across the brain's surface, which may trigger the aura symptoms and set off the cascade of pain. Researchers are still working to understand exactly how this electrical event connects to the chemical changes and pain.

Migraines versus other serious headache conditions

A sudden, severe headache that is completely different from your usual migraines can signal something serious like a stroke, meningitis, or a ruptured blood vessel. Seek immediate medical attention if you experience a headache that is the worst of your life, comes on suddenly with no warning, is accompanied by fever, stiff neck, confusion, vision loss, difficulty speaking, weakness, or numbness.

Chronic daily headaches—headaches occurring 15 or more days per month—are different from migraines and may develop if you take pain medication too frequently. Medication overuse headache is a real condition that requires a different treatment approach than migraine itself.

Cluster headaches are another distinct condition: they cause severe one-sided pain around the eye, come in groups over weeks or months, and are much rarer than migraines. They respond to different treatments. If your headache pattern changes significantly or you develop new symptoms, your doctor should evaluate whether something else is happening.

Frequently Asked Questions

Can you have a migraine without a headache?

Yes. Some people experience aura symptoms—flashing lights, blind spots, or tingling—without the headache pain that follows. This is called silent migraine or acephalgic migraine. The neurological event is still happening; the pain component is just absent. If this happens to you, mention it to your doctor because it can still affect your safety, especially while driving.

Is a migraine the same as a stroke?

No, but migraine with aura can sometimes look similar because both involve temporary vision or neurological symptoms. A migraine aura is reversible and resolves within an hour; a stroke causes permanent damage. If you have sudden weakness, facial drooping, speech difficulty, or symptoms that do not resolve, seek emergency care immediately. If you have a new type of migraine or your pattern changes, tell your doctor.

Why do migraines run in families?

Migraines have a genetic component—if both your parents have migraines, your risk is higher. Researchers have identified several genes that affect how your brain handles serotonin, CGRP, and other migraine-related chemicals. However, genetics is not destiny; environmental factors and triggers also play a major role in whether and when you develop migraines.

Can stress alone cause a migraine?

Stress is a common trigger, but it is usually not the only factor. You might notice migraines happen after stress ends, not during it—this is called a letdown migraine. Stress combined with other factors like poor sleep, skipped meals, or hormonal changes makes a migraine more likely. Identifying your personal combination of triggers helps you understand your pattern.