Cells in your brain make everything in your body work by sending electrical signals to each other. A seizure happens when there is a sudden change in how the brain cells send these signals to each other.
Some cells send abnormal signals, which stop other cells from working properly.
These abnormal signals result in a temporary change in sensation, behavior or movements, or thinking or consciousness. While a grand mal seizure causes the person to lose consciousness with the body stiffening and jerking uncontrollably, many other types of seizures have more subtle manifestations such as episodes of staring with repetitive movements or periods of altered awareness. Epilepsy is the name of the condition in which a person has repeated seizures. It is actually a group of more than 40 neurological conditions that share the common symptom of seizures. Epilepsy can result from head injury, infection, fever, brain tumors or other trauma that damages the brain.