When is it a seizure and when is it fainting? What the sources describe and what only your doctor can decide
Seizure or fainting? What the ESC guideline, NHS and Epilepsy Action describe, what to write down, and what only your doctor can decide.
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You wake up on the floor with no memory of how you got there. Was it a seizure or fainting? The two can be confused. This text collects what the ESC guideline, the NHS and the German health information site Gesundheitsinformation.de describe. It also shows what to write down for your appointment. Deciding which one it was is up to your doctor. If you already live with epilepsy, the end of the text shows what the seizure diary in Sam offers.
What happens during a seizure vs. fainting
Gesundheitsinformation.de says specialists speak of epilepsy only when seizures without an obvious trigger occur repeatedly. Generalized seizures involve the whole brain. Focal seizures start in one area of the brain.
Fainting, or syncope, has a different cause. The 2018 ESC guideline defines it as a transient loss of consciousness due to reduced blood flow to the brain. It has a rapid onset and a short duration, and recovery is spontaneous and complete.
The same guideline lists seizures in a table of conditions that may be incorrectly diagnosed as syncope. It says a detailed clinical history lets physicians tell syncope from other forms of transient loss of consciousness in about 60% of cases. So a good description counts.
Key observable differences
The points below repeat what sources describe. They are not a self-test.
The NHS describes a tonic-clonic seizure as one where you become unconscious and may fall, your muscles get stiff and your body jerks and shakes. Gesundheitsinformation.de adds that some people with focal seizures smack their lips, grimace or stammer. Others walk around without purpose or fumble with objects.
As symptoms of fainting, the NHS lists dizziness, sweating, feeling warm or hot, feeling sick and changes to vision. For reflex syncope, the ESC guideline lists pallor, sweating or nausea before the event. It also lists prolonged standing among the features.
Some of this only the person notices. Other parts only witnesses see. Gesundheitsinformation.de says people often remember a seizure poorly. It then makes sense to bring someone who saw it to the appointment.
After a stronger epileptic seizure, some people need time to come round. Gesundheitsinformation.de says some are exhausted in the hours afterwards and sleep a lot. It adds that depressive symptoms, forgetfulness, speech problems or paralysis can also occur, and that they pass again. For syncope, the ESC definition names spontaneous, complete recovery.
Absence seizures and focal seizures
Not every seizure ends with a fall. Gesundheitsinformation.de calls absences a mild form of seizure with sudden, brief pauses in consciousness. The NHS says you briefly lose awareness of what is going on around you.
The ESC guideline lists complex partial seizures and absence epilepsy in the same table. Its note for them reads: no falls, yet unresponsive and later amnesia. Whether an event fits this is for a specialist to decide.
Common seizure triggers and the importance of tracking
Epilepsy Action lists tiredness or poor sleep, missed doses of epilepsy medicine, alcohol in larger amounts, a high temperature from an infection and stress. Gesundheitsinformation.de also names flickering light for some people. Only around 3 to 5 in 100 people with epilepsy have seizures triggered by flashing or flickering lights (Epilepsy Action). Flashing lights are not a trigger for everyone.
For people with epilepsy, the NHS advises keeping a diary to help identify things that might trigger a seizure. Its examples are tiredness, stress, your period, flashing lights, food or drink. The post Sleep and epilepsy triggers: what your data can reveal covers how sleep data from Apple Health fits alongside such a diary.
When to seek medical evaluation
An unexplained loss of consciousness is worth discussing with a doctor, whether you think it was a seizure or fainting. Your doctor decides which tests make sense. Gesundheitsinformation.de names tests such as an EEG and an MRI scan for suspected epilepsy. Sorting out the cause is a job for a doctor.
Write down what you know. Note date and time, what came before, what witnesses saw and how you felt afterwards. Ask witnesses for their own description. The NHS says specialists ask what happened before, during and after the seizure.
First aid is a separate topic. The Deutsche Epilepsievereinigung explains it on its page Erste Hilfe (in German, page dated 2 November 2024). It also says when an emergency doctor should be called. In an emergency, call your local emergency number (112 in the EU, 999 in the UK, 911 in the US).
Log seizures in Sam and take the record to your neurologist
In Sam's epilepsy program you log what you or someone who saw it can tell you, so your neurologist gets a record instead of a recollection.
- Instead of notes: each entry holds date, time, type (focal aware, focal impaired awareness, tonic-clonic, absence or not sure), whether you lost consciousness, any injury, whether someone saw it, a suspected trigger and a free note.
- Instead of Apple Health alone: for an entry made today, sleep, HRV and resting heart rate sit next to it if Apple Health has values. Back-dated entries get none.
- Instead of memory: you create a report for your neurologist as a PDF, and a medicine with fixed daily dose times can remind you at those times.
The diary holds only what you log, and the program is for epilepsy a doctor has confirmed.
Try Sam HealthSam is a wellness companion, not a medical device. The app does not diagnose, treat, cure or prevent any condition or health state and does not replace medical advice.
Sources
Last updated: October 2026
- Gesundheitsinformation.de (IQWiG, in German): Epilepsie, page dated 5 April 2023
- Deutsche Epilepsievereinigung (in German): Erste Hilfe, page dated 2 November 2024
- ESC: 2018 ESC Guidelines for the diagnosis and management of syncope. Eur Heart J 2018;39(21):1883, definition and Tables 4 and 5
- NHS: Fainting, last reviewed 17 August 2026
- NHS: Epilepsy, last reviewed 6 March 2025
- Epilepsy Action: Seizure triggers, page dated November 2025, and Photosensitive epilepsy, page dated January 2026
More on Epilepsy
Frequently Asked Questions
Can a seizure look exactly like someone fainting?+
They can be confused. The 2018 ESC syncope guideline lists seizures in a table of conditions that may be incorrectly diagnosed as syncope. It says a detailed clinical history lets physicians tell syncope from other forms of transient loss of consciousness in about 60% of cases. That is why a precise description from you and from witnesses matters. Your doctor makes the call.
How can I tell if I had a seizure or fainted?+
Your doctor decides which one it was. The sources describe some features. For a tonic-clonic seizure, the NHS lists loss of consciousness, a possible fall, stiff muscles and a body that jerks and shakes. As symptoms of fainting, the NHS lists dizziness, sweating, feeling warm or hot, feeling sick and changes to vision. Write down what you remember and ask witnesses what they saw.
What should I do if someone has a seizure?+
The Deutsche Epilepsievereinigung explains first aid on its page Erste Hilfe (in German, page dated 2 November 2024). It also says when an emergency doctor should be called. The NHS epilepsy page says when to call 999 in the UK. In an emergency, call your local emergency number (112 in the EU, 999 in the UK, 911 in the US).
What triggers epileptic seizures?+
Epilepsy Action lists tiredness or poor sleep, missed doses of epilepsy medicine, alcohol in larger amounts, a high temperature from an infection and stress. Gesundheitsinformation.de, the German health information site, also names flickering light for some people. Only around 3 to 5 in 100 people with epilepsy have seizures triggered by flashing or flickering lights, according to Epilepsy Action. Your own triggers are a question for your neurologist.
What is an absence seizure?+
The NHS describes an absence seizure as one where you briefly lose awareness of what is going on around you. The ESC guideline lists absence epilepsy among conditions that can be incorrectly diagnosed as syncope. Its note reads: no falls, yet unresponsive and later amnesia. Whether an event was an absence is for your neurologist to decide. In the seizure diary in Sam you can choose Not sure.
What should I note down for my appointment if I am not sure what happened?+
Write down what you know: date, time, what came before and how you felt afterwards. Ask witnesses for their own description. Gesundheitsinformation.de says people often remember a seizure poorly, so bringing someone who saw it helps. The NHS says specialists ask what happened before, during and after the seizure.
Seizure detection: what can the Apple Watch do, and what does Sam do?+
That is not something Sam does: Sam does not detect seizures and does not predict them. A seizure is in your diary only if you log it. What the Apple Watch itself can do is listed on apple.com. Apps from other companies advertise seizure detection with a watch. Whether anything like that suits you is a question for your neurologist.