Epilepsy is a condition that causes seizures — temporary glitches in the brain’s electrical activity. These electrical disruptions can cause a range of symptoms. Some people stare off into space, some make jerky movements, while others lose consciousness.

Doctors don’t know what causes epilepsy. Genes, brain conditions like tumors or strokes, and head injuries may be involved in some cases. Because epilepsy is a brain disorder, it can affect many different systems throughout the body.


Epilepsy may stem from changes in the brain’s development, wiring, or chemicals. Doctors don’t know exactly what causes it, but it can start after an illness or damage to the brain. The disease disrupts the activity of brain cells called neurons, which normally transmit messages in the form of electrical impulses. An interruption in these impulses leads to seizures.

There are many different kinds of epilepsy, and different types of seizures. Some seizures are harmless and barely noticeable. Others can be life-threatening. Because epilepsy disrupts brain activity, its effects can trickle down to affect just about every part of the body.

Cardiovascular system

Seizures can interrupt the heart’s normal rhythm, causing the heart to beat too slowly, too quickly, or erratically. This is called an arrhythmia. An irregular heartbeat can be very serious, and potentially life threatening. Experts believe some cases of sudden unexpected death in epilepsy (SUDEP) are caused by a disruption in heart rhythm.

Problems with blood vessels in the brain can cause epilepsy. The brain needs oxygen-rich blood to function properly. Damage to the brain’s blood vessels, such as from a stroke or hemorrhage, can trigger seizures.

Reproductive system

Although most people with epilepsy are able to have children, the condition causes hormonal changes that can interfere with reproduction in both men and women. Reproductive problems are two to three times more common in people with epilepsy than in those without the disorder.

Epilepsy can disrupt a woman’s menstrual cycle, making her periods irregular or stopping them altogether. Polycystic ovary disease (PCOD) — a common cause of infertility — is more common in women with epilepsy. Epilepsy, and its medications, can also lower a woman’s sex drive.

About 40 percent of men with epilepsy have low levels of testosterone, the hormone responsible for sex drive and sperm production. Epilepsy drugs can dampen a man’s libido, and affect his sperm count.

The condition can also have an effect on pregnancy. Some women experience more seizures while they’re pregnant. Having a seizure can increase the risk of falls, as well as of miscarriage and premature labor. Epilepsy medicines can prevent seizures, but some of these drugs have been linked to an increased risk for birth defects during pregnancy.

Respiratory system

The autonomic nervous system regulates body functions like breathing. Seizures can disrupt this system, causing breathing to temporarily stop. Interruptions in breathing during seizures can lead to abnormally low oxygen levels, and may contribute to sudden unexpected death in epilepsy (SUDEP).

Nervous system

Epilepsy is a disorder of the central nervous system, which sends messages to and from the brain and spinal cord to direct the body’s activities. Disruptions in electrical activity in the central nervous system set off seizures. Epilepsy can affect nervous system functions that are voluntary (under your control) and involuntary (not under your control).

The autonomic nervous system regulates functions that aren’t under your control — like breathing, heartbeat, and digestion. Seizures can cause autonomic nervous system symptoms like these:

  • heart palpitations
  • slow, fast, or irregular heartbeat
  • pauses in breathing
  • sweating
  • loss of consciousness

Muscular system

The muscles that enable you to walk, jump, and lift things are under nervous system control. During some types of seizures, muscles can either become floppy or tighter than usual.

Tonic seizures cause the muscles to involuntarily tighten, jerk, and twitch.

Atonic seizures cause a sudden loss of muscle tone, and floppiness.

Skeletal system

Epilepsy itself doesn’t affect the bones, but drugs you take to manage it can weaken bones. Bone loss can lead to osteoporosis and an increased risk for fractures — especially if you fall while having a seizure.

Digestive system

Seizures can affect the movement of food through the digestive system, causing symptoms such as:

  • abdominal pain
  • nausea and vomiting
  • pauses in breathing
  • indigestion
  • loss of bowel control

Epilepsy can have ripple effects on just about every system in the body. Seizures — and the fear of having them — can also cause emotional symptoms like fear and anxiety. Medicines and surgery can control seizures, but you’ll have the best results if you start taking them as soon as possible after you’re diagnosed.