18 Causes and Triggers of Seizures

2. Local Seizure

A local seizure, also called a focal seizure, begins in one area of your brain. Groups of nerve cells send out abnormal electrical signals in a limited part instead of the whole brain. Unlike generalized seizures, the unusual activity does not spread across both sides from the start.

You may stay aware during a local seizure or lose awareness for a short time. The symptoms depend on where the seizure starts. If it begins in the part of your brain controlling movement, you might have jerking in one arm or leg. If it starts in an area that helps you sense things, you may smell, taste, or see something that is not there.

Some people experience a warning before the seizure starts, called an aura. This sign can include strange feelings, sounds, or visions that help you know one is coming.

3. Epilepsy

Epilepsy is a brain disorder that causes repeated seizures. Groups of nerve cells in your brain send out abnormal electrical signals, leading to changes in movement, sensation, or awareness for short periods.

You may have epilepsy if you experience more than one seizure not linked to a temporary condition like fever or head injury. Sometimes doctors find the cause, but in many people, it remains unknown. Brain injury, stroke, infection, or genetic factors can make epilepsy more likely.

The type of seizure you have depends on where the unusual activity starts in your brain. Some seizures cause brief staring or muscle twitches, while others lead to full-body shaking or loss of consciousness. Not all seizures look the same, and they can last from a few seconds to several minutes.

Treatment often includes taking an antiseizure medication to control electrical activity in your brain. If medicines do not help, other options include surgery, special diets, or nerve stimulation therapies. Managing epilepsy also involves maintaining good sleep, avoiding triggers, and following your doctor’s plan.

4. Low Oxygen During Birth

When a baby does not receive enough oxygen during birth, brain cells may become damaged. This condition, sometimes called birth asphyxia, affects how the brain sends and receives signals. The lack of oxygen can disturb normal brain activity and increase the risk of seizures soon after delivery.

You might notice signs of this problem if a newborn is slow to breathe, has a weak cry, or appears unusually limp. These symptoms show that the brain and other organs may not have received enough oxygen during labor or delivery. Early medical care can reduce the risk of permanent injury, but seizures may still occur in the hours or days that follow.

Low oxygen during birth can result from several situations, such as long or difficult labor, a compressed umbilical cord, a detached placenta, or severe maternal infection. Each of these issues can slow oxygen flow to the baby’s brain and other organs.

5. Brain Tumor

A brain tumor can cause seizures by disrupting normal electrical activity in your brain. The tumor presses on or damages nearby brain tissues and nerves. These sudden bursts of electrical activity can lead to seizures, which may appear as jerking movements, changes in behavior, or brief loss of awareness.

You can experience seizures before a brain tumor is even diagnosed. In some people, a seizure is the first sign that something is wrong in the brain. Tumors that grow near areas controlling movement, speech, or vision are more likely to trigger seizures because those regions handle active communication between brain cells.

Seizures caused by brain tumors vary from person to person. Some last only a few seconds and cause you to stare blankly, while others may cause full-body shaking. Afterward, you might feel confused or tired for a short time. Seizures do not always mean the tumor is cancerous. Both benign (noncancerous) and malignant (cancerous) tumors can affect how your brain cells work and may cause similar seizure patterns.

6. Brain Damage

When your brain tissues are injured, the normal electrical signals that control body functions and movement can be disrupted. This interruption can cause nerve cells to send confusing or excessive impulses, which may result in a seizure. Even a small area of damage can affect communication between brain cells.

Brain damage can occur for many reasons. Common causes include head injuries, stroke, infection, or lack of oxygen to the brain. Damage at birth or during infancy can also increase the risk. In some people, seizures may begin weeks or months after the injury, as the brain tries to heal and build new connections.

The part of the brain that is damaged often determines the effects you experience. For example, a person with damage in the motor area might have muscle jerks, while damage in the temporal region might lead to memory or emotional changes.

7. Triggers

You may notice that certain things make seizures more likely to happen. These are known as triggers. Not everyone with seizures has the same triggers, and some people may not have any at all.

Common triggers include lack of sleep, stress, and missing medication doses. Skipping or changing medicine without guidance can suddenly change the balance of electrical activity in your brain. A sudden drop in blood sugar from not eating on time may also serve as a trigger.

Other triggers can involve flashing lights or patterns, loud noises, or strong smells. These sensory changes can overload the brain and lead to seizures in some people, especially if they are already sensitive to light or sound. Physical triggers such as fever, dehydration, or illness can also increase seizure risks. Alcohol or illegal drug use, or sudden withdrawal from them, may disturb your brain’s normal activity.

Hormone changes during menstrual cycles or pregnancy sometimes act as triggers too. Environmental conditions like heat, fatigue, or overexertion can push your body past its limits and raise the chance of an episode.

8. Excitement

Excitement can trigger a seizure in some people, especially those with certain types of epilepsy. When you feel strong emotions like joy, anticipation, or fear, your body releases adrenaline and other stress hormones. These chemicals increase brain activity, which may cause the nerve cells to fire too quickly and lead to a seizure.

Emotional triggers affect people differently. What excites one person may overwhelm another. You might notice that special events, celebrations, or sudden surprises make you feel overstimulated. In rare cases, this overstimulation can cause abnormal electrical signals in the brain that set off seizure activity.

Physical changes linked to excitement, such as a fast heartbeat, faster breathing, or sudden changes in blood pressure, can also stress your nervous system. If your brain is sensitive to these shifts, the extra stimulation can make it harder for it to stay stable.

9. Strong Emotion

Strong emotions can sometimes trigger seizures in people who are sensitive to sudden stress or intense feelings. When you feel emotions such as fear, excitement, anger, or anxiety, your body releases stress hormones that can change how your brain’s electrical signals work. These changes may make your brain more likely to have abnormal electrical bursts that lead to a seizure.

You might notice that seizures happen more often during periods of emotional strain. This does not mean emotions alone always cause them, but that emotions can act as a trigger when other risk factors are present. For example, lack of sleep, missed medication, or illness can combine with strong stress to start a seizure.

Keeping track of your emotional patterns can help you recognize possible triggers. Some people find that relaxation methods such as deep breathing or gentle exercise lower their stress levels. Others benefit from talking with a mental health professional to learn ways to manage daily pressures.

10. Drug Use

Drug use can affect the brain’s electrical activity and sometimes trigger seizures. Both illegal and legal substances may cause this effect when taken in excessive amounts or when stopped suddenly after long use. These changes disturb how brain cells send and receive signals.

Drugs that stimulate or depress the nervous system raise the risk. Stimulants, such as those found in some illegal drugs, increase brain activity and may cause the neurons to fire too fast. Depressant drugs slow the brain and can also lead to seizures during withdrawal when the body reacts to the sudden change.

Some prescription medicines, especially those that act on the brain, may lead to seizures if misused, mixed with alcohol, or stopped without medical care. People who use or withdraw from substances such as alcohol, sedatives, or opioids may experience seizures because their brains struggle to rebalance chemical activity.

11. Infection

Infections can sometimes cause seizures because they disturb normal brain function. When germs enter the brain or nearby tissues, inflammation can occur. This swelling interrupts the way your brain cells send and receive electrical signals, which may lead to a seizure.

Meningitis and encephalitis are two common infections linked to seizures. Meningitis affects the membranes covering the brain and spinal cord, while encephalitis directly affects brain tissue. Both conditions can cause fever, confusion, and neck stiffness along with seizures.

Infection-related seizures may also follow other illnesses that cause high fever, especially in children. These are called febrile seizures. They usually last only a few minutes and do not always mean the child has epilepsy.

Other infections, such as malaria, HIV, or brain abscesses, may also trigger seizures in certain cases. When the body fights infection, chemical and electrical changes happen in the brain. If these changes become extreme, a seizure can occur.

12. Lights

Bright or flickering lights can trigger seizures in some people. This kind of sensitivity is called photosensitive epilepsy. Certain flashing or patterned lights cause sudden bursts of electrical activity in your brain.

Strobe lights, video games, or flashing images on screens often cause this reaction. Even sunlight reflecting off water or snow can create problems. Not everyone with epilepsy is affected by light, but for those who are, rapid or flickering visual patterns present a significant risk.

The flashing rate, brightness, and color contrast of a light all play a role. Lights flashing between 5 and 30 times per second are more likely to trigger a seizure. Watching screens from a close distance or in a dark room also increases the chance of a reaction. Using tinted lenses or adjusting screen brightness helps some people reduce problems. Sitting farther from a screen and keeping the room well lit may also help.

13. Music

Music can affect your brain in many ways, and in rare cases, it can trigger seizures. This is sometimes called musicogenic epilepsy. Seizures happen when certain sounds or musical patterns overstimulate areas of your brain that control hearing and emotion.

You might notice that seizures begin when you listen to a specific song, rhythm, or even a musical instrument. It does not matter if the music is live or recorded. What matters is how your brain reacts to the sound. The brain’s temporal lobes, which process hearing and memory, often play a role in this reaction.

Some people are more sensitive to sound triggers than others, possibly due to brain wiring, past head injury, or an existing seizure disorder. Not everyone with epilepsy will have music-triggered seizures, and these cases are uncommon.

Keeping track of seizure occurrences alongside exposure to music can provide useful information for healthcare providers. They may suggest an electroencephalogram to track brain activity while you listen to music.

14. Stroke

A stroke happens when blood flow to part of your brain suddenly stops or becomes severely reduced. Without enough blood, brain cells lose oxygen and begin to die. This damage interrupts the brain’s normal electrical signals, which may lead to a seizure.

There are two main kinds of stroke: ischemic and hemorrhagic. An ischemic stroke happens when a blood vessel is blocked, often by a clot. A hemorrhagic stroke happens when a blood vessel bursts and leaks blood into the brain tissue. Both conditions can leave scars or injured areas in the brain that may later trigger abnormal electrical activity.

You may have a seizure soon after a stroke, or one may appear months or even years later. The risk is higher if the stroke affects the outer layers of the brain or is more severe.

15. Stress

Stress happens when your body reacts to pressure, demands, or challenges. It can come from work, school, family issues, or sudden life changes. Short-term stress may help you stay alert, but when it lasts too long, it can affect your brain and body in harmful ways.

When you stay under constant stress, your body releases certain hormones that change brain activity. These changes may cause your brain’s electrical signals to become more unstable. For someone with epilepsy or a history of seizures, this instability can sometimes trigger an episode.

Even for people without epilepsy, extreme stress can disturb sleep, increase heart rate, and lower the brain’s ability to stay balanced. Stress can also lead to poor habits that make seizures more likely. Skipping meals, not getting enough sleep, or using alcohol can all affect the brain’s normal rhythm. Over time, this weakens your body’s ability to manage electrical activity in the brain.

16. Tiredness

When you do not get enough rest, your brain becomes more sensitive to changes in activity. This makes it harder for nerve cells to work normally. In people who are prone to seizures, tiredness lowers the brain’s ability to control electrical signals, which may trigger a seizure.

Sleep affects how the brain recovers and stays balanced. Missing one night of good sleep may not cause a seizure for everyone, but repeated lack of rest increases the risk. Even mild sleep loss can make seizure control harder for those with epilepsy.

Medication schedules and lifestyle habits also play a part. If you take seizure medicines, skipping doses or taking them late can make tiredness worse and increase seizure chances. You may notice warning signs when tiredness pushes your body too far. These include headaches, slower thinking, or an unusual feeling before a seizure.

17. Alzheimer’s

Alzheimer’s disease can play a role in triggering seizures by disrupting how brain cells communicate. As the disease progresses and brain cells die, abnormal electrical activity may lead to seizures, especially in later stages. These episodes can range from mild staring spells to full convulsions.

As Alzheimer’s progresses, brain cells die and the brain tissue shrinks. These changes make it harder for nerve signals to travel normally. Seizures may happen at any stage but are more common when memory and thinking difficulties become severe. You might notice brief confusion, twitching, or repeated movements. Sometimes the person seems unresponsive for a short time, which can be mistaken for a memory lapse.

A healthcare provider may use tests such as EEG or brain scans to understand seizure activity in someone with Alzheimer’s. Doctors manage these seizures by prescribing antiseizure medications to control electrical activity in the brain.

18. Unknown

Sometimes, seizures happen without a clear cause. When doctors cannot find any reason after testing, they describe it as an unknown or idiopathic seizure. This means that even though brain activity changes during the event, the source of those changes is not identified.

You may have normal test results, such as brain scans or blood tests, but seizures still occur. This can be confusing and stressful, especially when every possible cause, like head injury, infection, or chemical imbalance, has been ruled out.

Some researchers think that unknown seizures could be linked to very small brain changes that current tests cannot detect. Others believe that genetics may play a hidden role even when there is no family history.

Doctors often provide the same type of care for people with unknown seizures as for those with known causes. The goal remains to reduce seizure frequency and protect your health while experts continue to study possible explanations.