A migraine is a neurological condition that causes intense, often throbbing head pain along with symptoms like nausea, light sensitivity, and difficulty concentrating. It’s far more than a bad headache. Migraine attacks unfold in distinct phases, involve complex changes in brain activity and blood flow, and can last anywhere from a few hours to three days.
How a Migraine Attack Unfolds
A migraine attack has up to four phases, though not everyone experiences all of them. The first, called the prodrome, can begin hours or even days before the actual headache. During this stage you might notice mood changes, fatigue, unusual food cravings, frequent urination, neck stiffness, or excessive yawning. These early warning signs are easy to dismiss, but recognizing them can give you a head start on treatment.
The second phase, aura, affects roughly one in four people with migraine. Aura typically builds over five minutes and lasts up to an hour. The most common form is visual: you might see shimmering lights, geometric patterns, or blind spots that slowly expand across your field of vision. Some people experience tingling in the face or hands, or have trouble finding words. Aura happens because a slow wave of electrical disruption moves across the surface of the brain at about 2 to 5 millimeters per minute, temporarily silencing normal nerve activity as it goes. Imaging studies show that blood flow and brain activity shift in patterns that match this wave, which is why visual symptoms often start small and spread.
The headache phase is what most people think of as the migraine itself. Pain is typically on one or both sides of the head and has a pulsing quality. It usually lasts several hours to three days and comes with nausea, sensitivity to light, sound, and smell, anxiety, and difficulty sleeping. Even modest physical activity can make the pain worse.
After the headache fades, you may enter the postdrome, sometimes called the “migraine hangover.” Fatigue, body aches, trouble concentrating, and lingering light sensitivity can persist for hours. Many people describe feeling drained or foggy during this phase, even though the pain is gone.
What Happens Inside Your Brain
Migraine involves a chain reaction in the nervous system. The process centers on the trigeminal nerve, the major pain pathway for the head and face. When this system activates, nerve fibers around blood vessels in the brain release a powerful signaling molecule called CGRP. CGRP is the most potent known dilator of blood vessels in the brain, and its release triggers a cascade: blood vessels widen, nearby tissue becomes inflamed, and immune cells called mast cells dump additional inflammatory chemicals into the area.
This inflammation further stimulates the trigeminal nerve fibers, which release even more CGRP, creating a self-reinforcing loop of pain signaling. The pain signals travel from the blood vessels to the brainstem and then up to higher brain centers, which is why a migraine can affect mood, cognition, and sensory processing all at once. It also explains why the pain feels like it’s pulsing: the inflamed, dilated blood vessels are responding to each heartbeat.
Common Triggers
Most people with migraine can identify specific triggers, though these vary widely. A large review of trigger data found the most frequently reported ones, ranked by how often people cite them:
- Stress (nearly 80% of people with migraine)
- Hormonal changes (about 65%, especially around menstruation)
- Skipping meals or fasting (57%)
- Weather changes (53%)
- Sleep disturbances (50%)
- Strong perfumes or odors (44%)
- Bright or flickering light (38%)
- Alcohol (38%, with red wine a particularly common culprit)
These triggers don’t cause migraine on their own. Instead, they lower the threshold at which the trigeminal system activates. Red wine, for example, contains compounds that cause platelets to release serotonin into the blood and can interfere with enzymes that break down histamine. Strong odors activate pain fibers in the nose that are directly wired to the same trigeminal pathway involved in migraine, prompting the release of inflammatory chemicals. This is why a smell that’s merely unpleasant for most people can spark a full attack in someone with migraine.
Episodic vs. Chronic Migraine
Migraine is classified by how often it occurs. Episodic migraine means you have 0 to 14 headache days per month. Chronic migraine means 15 or more headache days per month for at least three months, with at least eight of those days meeting the criteria for migraine. About 3% of people with episodic migraine transition to the chronic form each year, often driven by medication overuse, untreated depression, or increasing attack frequency.
The distinction matters because chronic migraine typically requires a different treatment approach, with a stronger emphasis on daily preventive therapy rather than treating individual attacks as they come.
Who Gets Migraines
Migraine is one of the most common neurological conditions worldwide. Women are affected at roughly twice the rate of men, largely because of the role estrogen fluctuations play in triggering attacks. Most people experience their first migraine in their teens or twenties, and attacks often become less frequent after age 50. There is a strong genetic component: if one of your parents has migraine, your chances of developing it are significantly higher.
How Migraines Are Treated
Treatment falls into two categories: stopping an attack once it starts (acute treatment) and reducing how often attacks happen (preventive treatment).
Acute Treatment
For mild to moderate attacks, over-the-counter pain relievers like ibuprofen are often effective, especially when taken early. For more severe attacks, a class of prescription medications called triptans remains the gold standard. A 2024 systematic review in the BMJ compared every major acute migraine drug head-to-head and found that triptans, particularly eletriptan and rizatriptan, were the most effective at eliminating pain within two hours. They work by targeting serotonin receptors on blood vessels and nerve endings, essentially reversing the dilation and inflammation that drive migraine pain.
Newer drugs called gepants work differently, blocking the CGRP molecule that fuels the inflammatory loop. While gepants have fewer cardiovascular side effects (making them an option for people who can’t take triptans), the BMJ analysis found their pain-relieving power was comparable to ibuprofen rather than to triptans. They do have a unique advantage: some gepants can be used for both acute and preventive treatment.
Preventive Treatment
If you’re having four or more migraine days per month and the attacks are significantly disrupting your life, preventive therapy is worth discussing with your doctor. Traditional options include certain blood pressure medications, antidepressants, and anti-seizure drugs, all of which were discovered to reduce migraine frequency by accident.
The most targeted preventive treatments are injectable antibodies that block CGRP or its receptor. The American Headache Society’s 2024 guidelines recommend these as first-line options for people with episodic migraine who have at least moderate disability. They’re given as a monthly or quarterly injection and typically reduce migraine days by 50% or more in people who respond.
When a Migraine Becomes an Emergency
Most migraine attacks, while miserable, resolve on their own or with treatment. A migraine that lasts longer than 72 hours is classified as status migrainosus, a prolonged attack that may need more aggressive intervention. In practice, most headache specialists begin treating a severe, unresponsive attack before the 72-hour mark. The first step is usually stronger medications taken at home, though some people need IV fluids and medication at an infusion center or emergency department.
Any migraine that feels different from your usual pattern deserves attention. Sudden onset of the worst headache of your life, headache with fever and a stiff neck, or new neurological symptoms like weakness on one side of the body can mimic migraine but signal something more serious.