Seizures produce a wide range of signs, from full-body convulsions to subtle staring spells that last only seconds. Not all seizures look dramatic. Some cause nothing more than a brief blank look, a strange taste in the mouth, or repetitive movements like lip smacking. Recognizing the full spectrum helps you respond quickly, whether it’s happening to you or someone nearby.
Tonic-Clonic Seizures: The Most Recognizable Type
The seizure most people picture when they hear the word involves two distinct phases. During the tonic phase, muscles suddenly stiffen, causing the person to fall. They lose consciousness and often let out a groan or yell, not from pain, but from air being forced past tightened vocal cords. This phase typically lasts 10 to 20 seconds.
The clonic phase follows immediately. Arms and legs jerk rhythmically as muscles rapidly contract and relax. Loss of bladder or bowel control is common. Convulsions usually last one to two minutes. If jerking continues beyond five minutes, or if a second seizure starts before the person regains consciousness, it’s a medical emergency called status epilepticus.
Warning Signs Before a Seizure Starts
Some people experience a warning, called an aura, in the moments before a seizure. Common auras include a rising feeling in the stomach, a sudden wave of fear or anxiety, a strong sense of déjà vu, or unusual smells that have no obvious source. Some people see flashing lights or feel tingling in one part of the body. These sensations are actually small focal seizures themselves, originating in one area of the brain before activity spreads.
Not everyone gets auras, and they don’t occur with every seizure type. But if you notice a consistent warning pattern, it can be valuable information for your care team and may give you a few seconds to get to a safe position.
Focal Seizures: Signs That Start in One Area
Focal seizures begin in one hemisphere of the brain, and their signs depend on which part is affected. They fall into two categories based on whether you stay aware during the event.
Focal Aware Seizures
You remain conscious throughout, but something feels clearly wrong. Symptoms might include shaking in one arm or leg, sudden nausea, flashing lights in your vision, or an unexplained smell. These episodes are sometimes dismissed as anxiety or a quirk because the person looks normal from the outside. The experience is brief, often under a minute, and you can typically describe what happened afterward.
Focal Impaired Awareness Seizures
Awareness is partially or fully disrupted at some point during the seizure. The hallmark sign is automatisms, which are repetitive, involuntary movements. The most common are oral automatisms like lip smacking, chewing, or swallowing, along with hand movements like picking at clothing, fumbling, or patting. More complex automatisms can include cycling leg movements or head rolling. The person appears awake but won’t respond normally to questions or their name. Afterward, they typically have no memory of the episode.
Absence Seizures: Easy to Miss
Absence seizures are especially common in children and look nothing like convulsions. The person stares blankly into space for about 10 seconds, sometimes up to 30 seconds, then snaps back to full alertness as if nothing happened. Subtle eyelid fluttering may be the only visible clue. These seizures can happen dozens of times a day, and parents or teachers often mistake them for daydreaming or inattention. The key difference is that during an absence seizure, the child cannot be roused by touch or voice until the episode ends on its own.
Seizure Signs in Infants
Seizures in babies look very different from those in older children and adults. Infantile spasms, which most commonly appear between 4 and 7 months of age, involve sudden body tensing, a brief forward bending of the arms, legs, or head (sometimes called a “jackknife” movement), back arching, grimacing, repeated head nodding, or eyes rolling upward. These spasms tend to happen in clusters, often right after waking. Individual spasms last only a second or two, making them easy to confuse with a startle reflex or colic. Multiple spasms grouped together, particularly if they follow a consistent pattern, are a much more concerning sign.
Non-Convulsive Seizures: The Quiet Type
Not all seizures involve visible shaking. Non-convulsive seizures can cause prolonged confusion, difficulty speaking, irrational behavior, or a persistent “daydreaming” look. Because there are no dramatic physical signs, these episodes are frequently missed or attributed to psychiatric causes, medication side effects, or fatigue. In their most serious form, non-convulsive status epilepticus involves continuous seizure activity with cognitive or behavioral changes lasting 30 minutes or more. Diagnosis requires brainwave monitoring because the outward signs are so subtle that even clinicians may not recognize what’s happening without it.
What Happens After a Seizure
The period immediately following a seizure, called the postictal state, has its own distinct set of signs. Confusion and disorientation are the most common, along with extreme fatigue, headache or migraine, muscle soreness, memory gaps, difficulty speaking, and mood changes including agitation, anxiety, or sadness. Some people experience temporary weakness or paralysis on one side of the body.
The postictal state lasts anywhere from a few minutes to a few days, with an average of five to 30 minutes. During this time, you may need to rest in bed and avoid activities that require significant mental or physical effort. Full recovery feels gradual, like slowly coming back to yourself.
When a Seizure Becomes an Emergency
A seizure that lasts longer than five minutes, or more than one seizure within a five-minute period without the person returning to normal consciousness in between, qualifies as status epilepticus. Signs include prolonged muscle spasms, clenched teeth, irregular breathing, drooling, rapid eye movements, and grunting sounds. This is a medical emergency because prolonged seizure activity can cause brain injury. If you’re timing someone’s seizure and it passes the five-minute mark, call emergency services immediately.
A first-ever seizure in someone with no epilepsy history also warrants emergency evaluation, regardless of how long it lasts. The same applies if the person is injured during a fall, has trouble breathing after the seizure ends, or is pregnant.