A migraine aura is a set of sensory disturbances, most often visual, that signal a migraine attack is on its way. About 30% of people who get migraines experience aura, which typically lasts between 5 and 60 minutes and appears 30 to 60 minutes before the headache pain begins. The disturbances can be strange and even alarming if you don’t know what’s happening: shimmering zigzag lines, blind spots, tingling in your hands, or difficulty finding words.
What Aura Looks and Feels Like
Visual symptoms are the most common type of aura. The classic version is a scintillating scotoma, a flickering, arc-shaped distortion that usually starts near the center of your visual field and slowly expands outward toward the edges. Some people describe it as a shimmering crescent or a zigzag pattern that looks like the walls of a fortress (which is why neurologists call it “fortification spectra”). Inside the arc, your vision may go partially blank or blurry. The whole thing typically drifts across your field of view over 20 to 30 minutes, then fades.
Not everyone gets the textbook zigzag lines, though. Some people see flashing lights, spots, or stars. Others experience a temporary blind spot without any shimmer at all. And roughly a quarter of people with aura get non-visual symptoms, either alongside the visual changes or on their own.
Sensory aura usually shows up as tingling or numbness that starts in your fingertips on one side, slowly creeps up your hand and arm, and sometimes reaches your face, lips, or tongue. The key word is “slowly.” Unlike a stroke, where numbness hits all at once, aura symptoms build and spread gradually over several minutes. Speech aura is less common but can be unsettling. You might struggle to find the right word, slur your speech, or have trouble understanding what someone is saying to you. These language disruptions are temporary and resolve as the aura fades.
What’s Happening in Your Brain
Aura is caused by a phenomenon called cortical spreading depression: a slow wave of intense electrical activity that rolls across the surface of your brain, followed immediately by a period where those neurons go quiet. Picture a stadium wave moving through a crowd. As the wave passes through visual processing areas, you see the zigzag lines. When it reaches areas responsible for sensation or language, you get tingling or word-finding trouble.
This wave moves at about 3 to 5 millimeters per minute, which is why aura symptoms build gradually rather than appearing all at once. As the wave spreads, it triggers inflammation around blood vessels in the membranes surrounding the brain and activates pain-signaling pathways. That inflammatory cascade is what eventually produces the throbbing headache that follows. So the aura isn’t just a warning sign. It’s the opening act of the same biological event that causes the pain.
Aura vs. Prodrome
Many people confuse aura with the prodrome phase, but they’re distinct stages of a migraine attack. Prodrome comes first, sometimes hours or even days before the headache, and involves subtler, whole-body symptoms: unusual fatigue, irritability, food cravings, neck stiffness, frequent yawning, difficulty concentrating, or sensitivity to light and sound. These are more like background mood and energy shifts than the dramatic sensory disruptions of aura.
Aura, by contrast, lasts 5 to 60 minutes and produces specific, noticeable changes in your senses. You might experience prodrome without aura, aura without a noticeable prodrome, or both in sequence. Recognizing the prodrome is useful because it gives you an earlier window to prepare, while aura tells you that headache pain is likely minutes away.
Timing and What to Do During Aura
Most auras begin 30 to 60 minutes before the headache phase, though some people get aura during the headache itself, and a small number experience aura with no headache at all (sometimes called “silent migraine”). The aura phase almost always resolves within an hour.
Because aura gives you a relatively predictable window before pain starts, it’s a useful trigger point for treatment. If you have a prescribed medication for stopping migraines early, the onset of aura is generally when you want to take it. The goal is to interrupt the inflammatory process before the headache fully develops. Talk with your provider about the specific timing that works best for your medication, since some work better when taken during aura and others are more effective once head pain actually begins.
Beyond medication, practical steps during aura can help. Moving to a dim, quiet room reduces sensory load. If you’re driving when aura starts, particularly visual aura, pull over. Visual disturbances can meaningfully impair your ability to see the road, and they’ll pass within the hour.
Stroke Risk and Hormonal Birth Control
People who get migraine with aura have roughly double the risk of ischemic stroke compared to people without migraines. That sounds alarming, but the baseline risk of stroke in young, otherwise healthy people is very low, so doubling a small number still leaves you with a small number. Where this becomes clinically important is when other risk factors stack up.
The combination of migraine with aura, smoking, and estrogen-containing birth control creates a meaningfully elevated stroke risk, particularly in women under 45. Each factor alone raises risk modestly, but together they compound. If you experience aura, this is worth discussing with your healthcare provider when making decisions about contraception. Many providers recommend progestin-only or non-hormonal methods instead of combination pills for people with aura, especially if smoking is also in the picture.
When Aura Symptoms Need Attention
Because aura symptoms overlap with signs of stroke and other serious neurological events, it’s important to know what’s typical for your own pattern. Aura that follows your usual progression, lasts under an hour, and is followed by your usual headache is generally not cause for alarm.
Symptoms that deserve urgent evaluation include: aura lasting longer than 60 minutes, one-sided weakness (which can signal a rare subtype called hemiplegic migraine or something more serious), aura that starts suddenly rather than building gradually, or any aura pattern that’s dramatically different from what you’ve experienced before. If you’re over 40 and experiencing visual disturbances for the first time with no prior migraine history, that warrants a medical workup to rule out other causes.