Types of seizure
There are many different types of seizures. Seizures are generally divided into two main types:
- Focal (also known as partial) seizures
- Generalised seizures
Focal seizures only affect one part of the brain. These types of seizures can sometimes be caused by a head injury, stroke, meningitis, a tumour or developmental abnormalities. Depending on the function of the affected part of the brain, this will then determine the type of focal seizure. They can either be seizures with full awareness or limited awareness.
Types of focal seizures are:
- Focal aware seizures (also known as simple partial seizures)
- Focal seizures with limited awareness (also known as complex partial seizures)
- Focal to bilateral tonic-clonic seizures (also known as secondary generalised seizures)
Generalised onset seizures (also known as generalised seizures)
Generalised seizures affect the whole of the brain. There will always be some loss of consciousness, even if for just a fraction of a second.
The most common types include:
- Tonic-clonic seizures
- Absence seizures
- Atonic seizures
- Tonic seizures
- Myoclonic seizures
To find out more about the different types of seizures, read our Seizures explained publication.
For more detailed information about specific seizure types and epilepsy, we have the following publications:
Not every person has a seizure trigger, many people will have seizures for no obvious reason. There are, however, certain events that can be seizure triggers for some people, these include:
- Forgetting to take medication or taking it too late
- Lack of sleep and tiredness
- Drinking alcohol, particularly binge drinking
- Taking recreational drugs
- High caffeine consumption, including energy drinks
- Hormonal changes, such as during monthly period, pregnancy or menopause
- Feeling unwell, running a fever, pain
- Extreme temperatures
- Stress and anxiety, sometimes even boredom or excitement
- Missing meals
- Flashing or flickering lights, called photosensitive epilepsy, see below
Less than three percent of people with epilepsy are affected by photosensitivity making this a rare type of epilepsy contrary to popular belief.
If affected, flashing or flickering lights, sunlight reflecting on water, dappled sunlight seen through trees, as well as repetitive patterns can all trigger a seizure.
Flashing or flickering content of television programmes or films is the most common source for photosensitive seizures. You will be tested for photosensitivity as part of your epilepsy diagnosis, and will be told whether you have photosensitive epilepsy or not.
To find out more about seizure triggers, check out our following publications:
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