Condition: Blackouts, seizures and epilepsy

Blackouts, seizures and epilepsy can all be frightening to experience. It’s important to distinguish between them so that you can receive the most effective care and treatment.

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What are the differences between
blackouts, seizures and epilepsy?

Blackouts, seizures and epilepsy often display the same symptoms, so it can be difficult to distinguish them from one another. These are however three different medical occurrences, and it is important that diagnostic testing is done to identify which one you may be suffering with. The main differentiators between blackouts, seizures and epilepsy are what causes them, and how frequently they occur.


The term “blackout” refers to any temporary alteration of awareness or consciousness, and blackouts may have a wide range of causes.

Blackouts may be as a result of sudden drops in blood pressure (similar to fainting), may have a cardiac cause, can be seen in sleep disorders, can have a psychological cause or maybe as a result of neurological dysfunction, such as a seizure or a condition such as epilepsy.


Seizures represent the sudden development of unregulated, abnormal electrical activity within the brain, resulting in a temporary disruption of neurological function. Depending on where in the brain and how widespread this electrical activity is, seizures may result in minor symptoms such as brief speech disturbance, tremor, or confusion, but if the electrical activity spreads throughout the brain, this can cause a generalised convulsion. In most cases, a person will experience a seizure and never have one again.

One-off seizures are most often caused by an acute factor such as a certain medication, high fever, alcohol or drug withdrawal, low blood sugar or sodium levels, lack of sleep, a head injury, stroke or brain infection.


Recurring seizures are due to a brain condition called epilepsy. Epilepsy describes the tendency to have recurrent seizures in the absence of a clear physical trigger, and is usually diagnosed in this setting after two or more seizures. Occasionally, epilepsy may be diagnosed after a single seizure, if investigations point to a high likelihood of another seizure.

Common causes of epilepsy include inheriting certain genes, or an abnormality in the structure of the brain (commonly as a result of scarring due to previous brain injury, stroke or infection, or abnormal development of the brain before birth).

What are the
common causes of these conditions?

Anyone can be affected by a blackout, seizure or epilepsy. Blackouts are very common due to the wide range of causes. Seizures are also not considered to be rare, with studies estimating that an individual has an 8% to 10% lifetime risk of having a seizure. The lifetime risk of developing epilepsy is 3%, with around 50 million people worldwide having the condition, making it one of the most common neurological diseases globally.

Genetic epilepsy syndromes will often come on in childhood or adolescence. In contrast, people over 65 years of age have the highest incidence of epilepsy of any age, accounting for almost a quarter of cases of new-onset epilepsy. This is because epilepsy is often related to brain injury or damage, which can be caused by age-related conditions such as a stroke.

Can adults develop these
conditions later on in life?

Genetic/hereditary epilepsy syndromes will often come on in childhood or adolescence. In contrast, it is very common for epilepsy related to brain injury or damage to come on later in life, which would be expected, since conditions like stroke are very age-related.

The incidence of epilepsy is age-related. It is highest in children under the age of 1 year old, but declines in early childhood and plateaus in adults to a rate of about 30-40 per 100000 new diagnoses per year. However, in the elderly it increases, with about 100-170 new diagnoses per 100000 per year. The prevalence rises significantly with age too. As people get older, they are more likely to have diseases or disorders of the brain that predispose to seizures, such as strokes, tumours, head injury or degenerative diseases.

Seizures in older people can sometimes be mistaken for cognitive decline, as limited seizures may cause intermittent confusion. Additionally, other causes of collapse, such as fainting due to blood pressure issues, or abnormal heart rhythms, are more common, and may be misdiagnosed as epilepsy, or may be diagnosed in error where epilepsy is the cause.

How are blackouts, seizures and epilepsy diagnosed?

It’s important to see a specialist if you experience symptoms of a blackout, seizure or epilepsy so that you can get a diagnosis and receive treatment if necessary. At OneWelbeck, our consultant neurologists will use specific tests to determine whether or not you had a blackout or a seizure, how likely it is you will have another event, and what caused it. Tests may include neurological tests, blood tests, a CT scan, an MRI scan and other types of imaging tests.

If you have had a blackout or seizure and do not know the cause, or have had multiple events, an electroencephalogram (EEG) will also be performed. An EEG is a test that records the electrical activity of your brain. This will reveal any patterns in activity that indicate whether or not a seizure is likely to reoccur and will help exclude conditions that mimic epilepsy so that a diagnosis of epilepsy can be confirmed or ruled out.

What are the treatment options for blackouts, seizures and epilepsy?

The most appropriate treatment will depend on the outcome of your tests. If epilepsy mimics have been excluded, and a seizure has been confirmed, the decision to initiate treatment is based upon the underlying cause and what the risk of further seizures is. If there is a clear acute physical trigger and no diagnosis of epilepsy, treatment may not be required in the long term.

If you are diagnosed with epilepsy, medication will be the most likely treatment. The drug recommended will be based on the type of epilepsy that is diagnosed, other medical issues you have and any other medications you are already taking. Other factors such as a planned pregnancy will also be taken into account. Other less usual treatments include surgery or implanted nerve stimulators, but these treatments are usually reserved for select individuals and are not appropriate for most people.

Blackouts, seizures and epilepsy Specialists

We have brought together a group of leading neurologists, neuroradiologists, and neurophysiologists to create our Neurology team. With over 300 years of combined experience, these expert clinicians are the best in their field providing services that integrate across multiple specialties.