Recent Blog Articles
Cutting and self-harm: Why it happens and what to do
Discrimination at work is linked to high blood pressure
Pouring from an empty cup? Three ways to refill emotionally
Give praise to the elbow: A bending, twisting marvel
Sneezy and dopey? Seasonal allergies and your brain
The FDA relaxes restrictions on blood donation
Apps to accelerometers: Can technology improve mental health in older adults?
Swimming and skin: What to know if a child has eczema
A muscle-building obsession in boys: What to know and do
Natural disasters strike everywhere: Ways to help protect your health
What Is It?
A seizure is a sudden change in the brain's normal electrical activity. During a seizure, brain cells "fire" uncontrollably at up to four times their normal rate, temporarily affecting the way a person behaves, moves, thinks or feels.
There are two major types of seizures:
- Primary generalized seizures – The seizure affects the entire cerebral cortex, the outer portion of the brain that contains the majority of brain cells. In this type of seizure, the abnormal firing of brain cells occurs on both sides of the brain at about the same time.
- Partial (focal) seizure – The abnormal firing of brain cells begins in one region of the brain and remains in that one region.
Many conditions can affect the brain and trigger a seizure, including:
To continue reading this article, you must log in.
Subscribe to Harvard Health Online for immediate access to health news and information from Harvard Medical School.
- Research health conditions
- Check your symptoms
- Prepare for a doctor's visit or test
- Find the best treatments and procedures for you
- Explore options for better nutrition and exercise
I'd like to receive access to Harvard Health Online for only $4.99 a month.Sign Me Up
Already a member? Login ».
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles.
No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.
Free Healthbeat Signup
Get the latest in health news delivered to your inbox!