The symptoms of epilepsy are seizures. A seizure happens when the normal electrical activity in your brain goes wrong.
There are lots of different types of seizures. They can look and feel very different, depending on where in the brain they start and how far and how quickly they spread. For example:
You may get a strange feeling, as though you're out of touch with your surroundings
Your muscles may feel stiff or limp
Your arms may jerk suddenly
You may twitch or tremble
You may black out and fall to the ground.
Some people get a warning sign, such as a strange smell or feeling, before their seizure starts. These are called auras. Other people get no warning and their seizure comes on suddenly.
Sometimes, seizures are set off by things such as lack of sleep or flashing lights. Doctors call these things triggers. (To learn more, see Things that trigger seizures.)
Once a seizure ends, some people know what happened to them, but others don't.
The length of seizures can vary. They can last for a few seconds or several minutes.
Most people don't get symptoms between seizures. But if their epilepsy is caused by a problem in the brain (such as a tumour, infection or an injury), then this may lead to other problems besides the seizures. Drug treatments for epilepsy may also cause headaches, rashes and other side effects.
Types of seizures
It's important to work out what type of seizure you or your child is having. This is because:
Seizures are usually divided into two main groups according to where they start in the brain and what happens to you during them:
But not all seizures can be grouped under these headings, especially those in babies. Doctors call these unclassified seizures.
It is possible to have a seizure that's caused by something else, not by epilepsy. (To learn more, see Non-epileptic seizures.)
Partial (focal) seizures: how they affect you
In a partial (focal) seizure, only part of the brain is affected. Symptoms depend on what that part of the brain does. (To learn more, see The parts of your brain and what they do.)
Partial seizures can be divided into simple partial seizures or complex partial seizures. 'Simple' means the person doesn't black out. 'Complex' means the person passes out or becomes less aware of his or her surroundings.
Epilepsy that causes partial seizures is sometimes called focal epilepsy and partial seizures are sometimes called focal seizures. This is because they start from a particular focus (which means area) of the brain.