Fits, Faints & Blackouts
EEG and expert neurologist assessment to tell seizure from syncope — and to find the actual cause.
Was It a Seizure or a Faint?
This is the single most important question after a blackout — and the most commonly mis-answered. Treatment, driving, and prognosis all depend on getting it right.
| Feature | Syncope (Faint) | Epileptic Seizure |
|---|---|---|
| Typical trigger | Standing up, pain, heat, dehydration, strong emotion, sight of blood | Often no trigger; some occur during sleep or on waking |
| Warning before | Lightheaded, hot, sweaty, tunnel vision, ringing ears | Sometimes a brief aura (smell, fear, déjà vu); often no warning |
| Duration of unconsciousness | Seconds — usually under 30 | Often 1 to 3 minutes |
| Jerking movements | Brief, irregular jerks can occur (convulsive syncope) | Sustained, rhythmic jerking is typical of a generalised tonic-clonic seizure |
| Tongue biting | Rare; if present, usually tip of tongue | Common; classically the side of the tongue |
| Incontinence | Can occur in either | Can occur in either |
| Recovery | Rapid — back to normal within a minute or two | Confusion lasting many minutes to hours is typical |
| During sleep | Very rare | Possible — significantly raises likelihood of epilepsy |
How EEG Fits Into the Workup
EEG is the right test for some blackouts — but not all. Here is how it fits with everything else.
When EEG is most useful
When the history suggests possible seizure — sustained jerking, tongue biting, prolonged confusion afterwards, occurrence during sleep, or no clear trigger. EEG looks for epileptiform discharges that support an epilepsy diagnosis.
When heart tests come first
When the history suggests cardiac syncope — collapse during exertion, brief warning, palpitations beforehand, or a family history of sudden cardiac death. ECG, Holter monitor and echocardiogram are the priority.
When autonomic testing helps
When fainting is recurrent and posture-related, with symptoms of dizziness on standing, palpitations, brain fog or exercise intolerance. Tilt-table and autonomic testing (including POTS testing) clarify whether the autonomic nervous system is involved.
Other Causes of Blackouts to Consider
Not every loss of consciousness is a seizure or a simple faint.
The classic faint — triggered, brief, with a clear warning.
Blood pressure drops on standing. Common in older adults and on certain medications.
Heart rhythm or structural cause. The most important not to miss.
Postural orthostatic tachycardia — dizziness and palpitations on standing.
Visual disturbance, occasionally with confusion. Rarely full loss of consciousness.
Low blood sugar — especially in those on diabetes treatment.
Hyperventilation can produce dizziness, tingling and a sense of unreality.
Real and treatable, but different from epileptic seizures. EEG helps make the distinction.
Frequently Asked Questions
What is the difference between a seizure and a faint?
A faint (syncope) is a brief loss of consciousness from reduced blood flow to the brain, usually with a recognised trigger. Recovery is rapid. An epileptic seizure is caused by an abnormal burst of brain electrical activity and is more likely to involve sustained jerking, side-of-tongue biting, prolonged confusion afterwards, or occurrence during sleep. The distinction matters because the treatments and driving implications are very different.
Can a faint cause jerking movements that look like a seizure?
Yes. Brief jerks during a faint (convulsive syncope) are very common and often misdiagnosed as epilepsy. The history of what triggered the event and what witnesses saw is what distinguishes them. EEG, ECG and sometimes tilt-table or autonomic testing are used together when the picture is not clear.
Do I need an EEG for a blackout?
Not every blackout needs an EEG. EEG is most useful when there are features suggesting a possible seizure — sustained jerking, side-of-tongue biting, prolonged confusion afterwards, occurrence during sleep, or no clear trigger.
What other tests might I need?
Depending on the picture: ECG, 24-hour heart monitor, echocardiogram, tilt-table testing, autonomic testing (including POTS testing), blood tests, or MRI of the brain. Often more than one test is needed to be confident about the cause.
Can I drive while my blackouts are being investigated?
There are specific rules in New South Wales about driving after blackouts and seizures. Your neurologist will explain the current rules and what they mean for your situation. Do not drive until you have had this conversation.
Get a Clear Answer About Your Blackouts
Same-day expert reporting. Specialist workup, not guesswork. Bondi Junction.