Epilepsy is diagnosed when a person has at least two unprovoked seizures more than 24 hours apart, or a single unprovoked seizure with a high likelihood (60% or greater) of having another within the next ten years. But recognizing that you’ve had a seizure in the first place isn’t always straightforward. Not all seizures involve convulsions or loss of consciousness, and many people don’t realize what happened until someone else describes it to them.
What Seizures Actually Look and Feel Like
Most people picture a seizure as falling to the ground and shaking. That does happen, but it’s only one type. Seizures fall into two broad categories based on where they start in the brain, and each produces very different experiences.
Focal seizures begin on one side of the brain. In their mildest form, you stay fully aware the entire time. You might feel an intense wave of déjà vu, a rising sensation in your stomach, or notice one hand or arm moving on its own. These episodes can be so brief and subtle that people dismiss them for years as anxiety or oddness. In a more disruptive form, focal seizures impair your awareness. You may look confused or dazed, smack your lips, pick at your clothing, or stare blankly. You won’t be able to respond to questions, and you probably won’t remember the episode afterward.
Generalized seizures involve both sides of the brain from the start and almost always cause a loss of consciousness. The most dramatic version is a tonic-clonic seizure: your muscles stiffen, you may cry out or fall, and then your body jerks rhythmically. But generalized seizures can also be nearly invisible. Absence seizures cause a brief blank stare lasting only a few seconds, sometimes with rapid blinking or small hand movements. In children especially, these get mistaken for daydreaming.
Signs You May Have Had a Seizure
Because many seizures alter awareness, you often have to piece together what happened from indirect clues. Waking up on the floor with no memory of falling, discovering you’ve bitten your tongue, or finding that you’ve lost control of your bladder can all point to a seizure that occurred while you were unaware. Unexplained muscle soreness, especially if it’s widespread and appeared suddenly, is another common signal.
The recovery period after a seizure, called the postictal state, is itself a telling sign. It typically lasts between five and 30 minutes but can stretch to a full day or longer after a severe episode. During this window, people commonly experience confusion, extreme fatigue, headache, difficulty speaking, memory gaps, and mood changes like anxiety or agitation. If you’ve ever “come to” feeling deeply exhausted and disoriented with no clear explanation, that pattern is worth paying attention to.
How Seizures Differ From Fainting
Fainting is the most common thing mistaken for a seizure, and the distinction matters because the causes and treatments are completely different. A fainting episode usually lasts less than a minute. Beforehand, you’ll often notice warning signs like tunnel vision, nausea, cold sweats, dizziness, or pale skin. Recovery is typically quick.
Seizures tend to last longer than a minute and involve features that fainting does not: sustained convulsions, tongue biting, loss of bladder or bowel control, lip smacking, random eye movements, or drooling. Brief jerking movements can happen with fainting too, which adds to the confusion, but prolonged rhythmic shaking is a seizure hallmark. The prolonged confusion and exhaustion afterward also points more toward seizure than a simple faint.
How Doctors Confirm a Diagnosis
No single test can definitively prove or rule out epilepsy. Diagnosis relies on combining your history, witness accounts, and several types of testing.
EEG (Brain Wave Recording)
An EEG measures electrical activity in the brain and looks for abnormal patterns associated with seizures. It’s the most important diagnostic tool, but it has a significant limitation: a standard EEG performed after a single seizure only picks up abnormalities about 17% of the time. The test is highly specific, meaning if it does show epileptic activity, that finding is very reliable. But a normal result doesn’t mean you’re in the clear. Sleep deprivation before the test, longer recording sessions, and repeat studies all improve detection rates. In ambiguous cases, doctors may use video-EEG monitoring, where brain activity is recorded continuously alongside video footage so that any episodes can be matched to what’s happening electrically in real time. This remains the gold standard for tricky diagnoses.
Brain Imaging
An MRI scan looks for structural problems in the brain that could be triggering seizures. These include scarring or shrinkage in the inner part of the temporal lobe (a common finding in temporal lobe epilepsy), abnormalities in how the brain’s outer layer developed before birth, blood vessel malformations, and areas of damage from prior injury, infection, or stroke. Finding one of these abnormalities doesn’t guarantee epilepsy, but it significantly increases the likelihood that a seizure will recur, which can push toward a diagnosis even after a single event.
Blood Tests
Blood work is mainly used to rule out other causes of seizure-like episodes, such as very low blood sugar, electrolyte imbalances, or infections. One specialized test measures a hormone called prolactin. When drawn within 10 to 20 minutes of an episode, prolactin levels that spike to three or four times their baseline suggest a true epileptic seizure rather than a nonepileptic event. This test is useful in specific clinical settings but isn’t part of a routine workup.
What Else It Could Be
Not everything that looks like a seizure is epilepsy. Psychogenic nonepileptic seizures (sometimes called PNES) are episodes that resemble seizures physically but are not driven by abnormal electrical activity in the brain. They’re associated with psychological factors like trauma, stress, or dissociative conditions. During a PNES episode, brain wave monitoring shows no change in cortical activity, which is why video-EEG is so valuable for telling the two apart. Roughly speaking, a notable percentage of people referred to epilepsy centers for uncontrolled seizures turn out to have PNES instead, and the treatment path is entirely different.
Other conditions that can mimic seizures include migraines with aura, panic attacks, sleep disorders like narcolepsy, transient ischemic attacks (mini-strokes), and certain heart rhythm problems that cause sudden loss of consciousness.
After a First Seizure: What the Numbers Say
If you’ve had one unprovoked seizure, the question on your mind is whether it will happen again. About one-third of adults have a second seizure within a year, and nearly half have one within two years. The risk is higher if your EEG shows epileptic activity, if your MRI reveals a structural abnormality, or if the seizure happened during sleep. When two or more of these risk factors are present, the probability of recurrence can cross the 60% threshold that meets the formal definition of epilepsy, even after just one event.
How to Prepare for a Neurology Visit
Because so much of epilepsy diagnosis depends on a detailed history, what you bring to your first appointment matters enormously. Many people don’t know what happens during their own seizures, so information from anyone who witnessed the event is critical. Ask a family member, partner, or friend to write down exactly what they saw: what your body did, how long it lasted, what your eyes were doing, and how you behaved afterward.
Start keeping a log of any episodes, even the ones you’re not sure about. Useful details include the date and time, what you were doing beforehand, how much sleep you’d gotten, whether you’d consumed alcohol or caffeine, any unusual sensations before the event (strange tastes, smells, visual disturbances, or that rising stomach feeling), and how you felt in the hours after. Smartphone apps designed for seizure tracking let you log this information quickly and can even store video. If someone is with you during an episode, a short video recording is one of the most valuable things you can show a neurologist, because it captures details that verbal descriptions often miss.
Patterns in timing, triggers, and symptoms help a neurologist determine not just whether you have epilepsy, but what type, which directly shapes treatment decisions.