A migraine is a multi-stage neurological event that unfolds over hours to days, involving far more than a bad headache. It typically moves through up to four distinct phases, each with its own set of symptoms driven by waves of abnormal brain activity, shifts in brain chemistry, and inflammation along pain-signaling nerves. About 3.1 billion people worldwide experience headache disorders, and migraine is among the most common, striking most often between ages 35 and 45 and affecting women more frequently than men, likely due to hormonal influences.
The Prodrome: Your Brain’s Early Warning
A migraine attack often begins hours or even days before any head pain starts. This first stage, called the prodrome, is your nervous system signaling that something has shifted. You might feel unusually tired, irritable, or have trouble concentrating. Some people notice neck stiffness, increased sensitivity to light or sound, nausea, or changes in bowel habits like constipation or diarrhea.
A few prodrome symptoms are distinctive enough to serve as reliable early warnings: excessive yawning, sudden cravings for specific foods (especially sweets), and frequent urination. These signals originate deep in the brain, where regions responsible for regulating sleep, appetite, and mood begin firing abnormally before the pain circuits fully activate. Not everyone recognizes their prodrome at first, but learning to spot these patterns can give you a window to act before the attack escalates.
What Happens During an Aura
Roughly one in four people with migraine experience an aura, a wave of temporary neurological symptoms that usually builds over at least five minutes and lasts up to an hour. Visual disturbances are the most common form: geometric patterns, shimmering or flashing lights, or blind spots that drift across your field of vision, typically in both eyes. Some people instead feel numbness or tingling that spreads through one hand and up the arm, have trouble finding words, or experience dizziness and ringing in the ears.
The biology behind aura is a phenomenon called cortical spreading depression. A slow wave of intense electrical activity sweeps across the surface of the brain, causing neurons to fire rapidly and then go silent. This wave moves through the cortex at a steady pace, which is why aura symptoms tend to shift and evolve gradually rather than appearing all at once. As this electrical wave passes, it triggers the release of inflammatory molecules. When those molecules reach the membranes surrounding the brain (the meninges), they set off the cascade that produces headache pain. In about 20% of people who get auras, the symptoms can last longer than 60 minutes, and some people experience aura after the headache has already begun rather than before it.
The Headache Phase: More Than Just Pain
The headache itself is the phase most people associate with migraine, and it typically lasts anywhere from several hours to three days. The pain is often described as throbbing or pulsating and tends to start on one side of the head, though it can spread to both sides or encompass the entire head. Physical movement makes it worse, which is why many people instinctively retreat to a dark, quiet room and stay still.
What drives this pain is a chain reaction in the trigeminal nerve system, the major pain-signaling network for the head and face. When activated, trigeminal nerve fibers release a signaling molecule called CGRP (calcitonin gene-related peptide) into the blood vessels surrounding the brain. CGRP dilates those blood vessels and triggers inflammation, which sensitizes nearby nerve endings. The inflammatory process then stimulates even more CGRP production, creating a self-reinforcing loop that sustains pain for hours to days. Meanwhile, fluctuations in serotonin, a chemical that helps regulate blood vessel width and nerve communication, cause blood vessels to constrict and then expand, contributing to the characteristic throbbing sensation.
Pain is only part of the picture. During the headache phase, your entire sensory system becomes hypersensitive. Light feels painfully bright (photophobia), ordinary sounds seem unbearably loud, and even mild smells can trigger nausea or vomiting. Many people also experience anxiety, insomnia, and difficulty thinking clearly. This sensory overload reflects a nervous system that has lost its normal ability to filter and dampen incoming signals.
The Postdrome: Why You Feel Drained Afterward
Even after the headache fades, the migraine isn’t over. Most people enter a recovery phase called the postdrome, often described as a “migraine hangover.” It can last a few hours or linger for up to two days. Common postdrome symptoms include deep fatigue, body aches (particularly a stiff neck), difficulty concentrating, dizziness, and lingering sensitivity to light and sound. Some people experience mood changes that range from mild depression to, surprisingly, a sense of euphoria.
During postdrome, your brain is essentially recovering from the neurological storm it just weathered. The fog and exhaustion reflect a nervous system that spent hours in a state of heightened activation and inflammation. Pushing through postdrome with intense activity or screen time often prolongs it, so rest during this window matters more than many people realize.
Why the Brain Gets Stuck in This Cycle
Migraine is not simply a blood vessel problem or a pain problem. It is a neurological disorder rooted in how the brain processes sensory information and regulates its own activity. In people prone to migraine, groups of excitable brain cells are more easily triggered into waves of abnormal activity. When these waves start, they release chemicals like serotonin and glutamate that alter blood vessel behavior and activate pain pathways. Hormonal shifts, particularly drops in estrogen, can set off these changes, which is one reason migraines are roughly two to three times more common in women.
The trigeminal system plays a central role in sustaining the attack. Once CGRP and other inflammatory peptides are released from trigeminal nerve fibers, they create a feedback loop: inflammation triggers more CGRP release, which deepens inflammation, which sensitizes pain pathways further. This process corresponds closely with the typical 4 to 72 hour duration of a migraine episode. Over time, in some people, this cycle becomes more frequent until headaches occur on 15 or more days per month for longer than three months, the threshold at which migraine is classified as chronic.
When a Migraine Becomes an Emergency
Most migraines, though miserable, resolve on their own or with treatment within three days. A migraine that continues uninterrupted beyond 72 hours with debilitating pain and symptoms is classified as status migrainosus, a complication that typically requires medical intervention. Brief periods of relief from sleep or medication (up to 12 hours) don’t reset the clock.
Certain symptoms during a headache should prompt immediate medical evaluation because they can signal something other than migraine: a sudden, explosive headache unlike any you’ve had before, headache with fever and a stiff neck, confusion or seizures, weakness on one side of the body that doesn’t resolve, or a new headache pattern after age 50. These red flags overlap with conditions like stroke or meningitis, where fast treatment changes outcomes dramatically.