Most people with epilepsy get some kind of warning before a seizure, and learning to recognize yours can give you precious seconds or even hours to prepare. These warnings fall into two distinct categories: early signals that appear hours to days beforehand, and immediate sensory changes that mark the very beginning of seizure activity in the brain. About 70% of people with epilepsy experience recognizable warning signs, regardless of their seizure type.
Early Warnings: Hours to Days Before
The earliest clue that a seizure may be approaching is called the prodrome. This is not part of the seizure itself. It’s a shift in how you feel that can begin hours or even days before anything happens. The most common prodromal symptoms are irritability, anxiety, confusion, headache, and mood changes like sudden anger or sadness. Some people describe a general sense that something is “off” without being able to pinpoint why.
Physical prodromal signs can include tremor, nausea, dizziness, numbness, or tingling. These symptoms are often subtle enough that people dismiss them at first. Over time, though, many people learn to connect these vague feelings to seizures that follow. The key is pattern recognition: what feels like a bad mood or an off day might actually be a reliable signal once you start paying attention.
The Aura: Seconds to Minutes Before
An aura feels like a warning, but it’s actually the seizure’s opening act. It’s a small focal seizure confined to one area of the brain, and you remain fully conscious during it. If the electrical activity stays contained, the aura may be the only thing that happens. If it spreads to both hemispheres, a larger seizure can follow within seconds to minutes.
What an aura feels like depends on which part of the brain is involved. Common experiences include:
- Taste or smell changes: a bitter or metallic taste, or a strange, unpleasant smell that isn’t there
- Visual disturbances: flickering vision, blurring, vision loss, or visual hallucinations
- Stomach sensations: nausea, stomach pain, or a rising feeling in the abdomen
- Emotional surges: sudden intense fear, joy, sadness, or anxiety that comes on without a clear reason
- Memory distortions: déjà vu (feeling like something has happened before when it hasn’t) or jamais vu (a familiar person or place suddenly feeling completely unfamiliar)
- Physical sensations: tingling, numbness, dizziness, or subtle twitching in an arm or leg
- Sound changes: ringing, buzzing, or auditory hallucinations
- Dissociation: an out-of-body sensation or feeling detached from your surroundings
Temporal lobe seizures are especially known for producing emotional auras, particularly sudden fear or déjà vu. These can be intense and disorienting, but recognizing them as seizure activity rather than random anxiety is what gives you the window to act.
How to Track Your Personal Pattern
Your warning signs are unique to you, and the best way to identify them is with a seizure diary. Track each seizure along with what you noticed in the hours and days leading up to it. Record your sleep quality, stress level, meals, menstrual cycle (if applicable), and any medications you missed. Over weeks or months, patterns often emerge that aren’t obvious in the moment.
Common triggers worth tracking include sleep deprivation, high stress, alcohol use, missed meals, illness, and flickering lights. Some people find their seizures cluster around specific times of day or phases of their menstrual cycle. Bringing this diary to your neurologist helps both of you see which warning signs are consistent and which triggers you can realistically avoid.
What to Do When You Feel One Coming
If you recognize a prodrome or aura, your first priority is physical safety. Move away from stairs, roads, water, sharp objects, and anything that could cause injury if you lose awareness. Sit or lie down on the ground if possible. If you’re driving, pull over immediately. Let someone nearby know what’s happening so they can stay with you and time the seizure if one occurs.
If your neurologist has prescribed a rescue medication, an aura may be the right time to use it. Several FDA-approved options exist for use outside a hospital, including nasal sprays that you or a bystander can administer quickly. These fast-acting medications can sometimes prevent a focal seizure from spreading into a full convulsive episode. Your neurologist will give you a specific plan for when and how to use rescue therapy based on your seizure pattern.
Anyone with you should know the basics: don’t hold you down, don’t put anything in your mouth, and turn you gently on your side if you’re lying down so your airway stays clear. If a convulsive seizure lasts longer than five minutes, that’s a medical emergency requiring a 911 call.
Seizure Alert Dogs
Some trained dogs can detect an oncoming seizure before anyone else notices, including the person having it. Research on seizure alert dogs found a median sensitivity of 80%, meaning they correctly warned of 8 out of 10 seizures. Notably, these dogs never gave a false alert in the study: every warning behavior was followed by an actual seizure. The lead time ranged from 10 seconds to 5 hours, with a median of about 2.5 minutes.
How they do it isn’t fully understood. Some families believe their dog picks up on subtle behavioral cues that humans miss, like tiny changes in movement or facial expression that happen early in seizure activity. Others suspect smell plays a role. Whatever the mechanism, these dogs can provide an additional layer of warning for people whose own prodromal or aura experiences are unreliable.
Wearable Seizure Detection Technology
Wearable devices are a growing option, though most current technology focuses on detecting seizures as they happen rather than predicting them in advance. One FDA-cleared wristband system uses motion sensors and sweat gland activity to detect convulsive seizures, catching 94% of them in real-world testing across 35 patients over nearly 2,500 days of monitoring. It averaged less than one false alarm every four days.
These devices are most useful for alerting caregivers when a seizure occurs, especially during sleep or when the person is alone. True seizure prediction, meaning a device that warns you before seizure activity begins, remains a more difficult technical challenge. For now, your own awareness of prodromal and aura symptoms is still the most reliable early warning system you have.