A temporary disturbance of the brain’s normal electrical patterns causes the uncontrolled muscle spasms that make up a seizure. Many different types of illnesses, conditions and consumed substances can cause a seizure to develop.

Fever is among the most common triggers of seizures in children. A febrile seizure can be triggered when a child's temperature has a sudden and severe spike to 102 degrees Fahrenheit (38.9 degrees Celsius) or more. Febrile seizures most often affect children between the ages of 6 months and 3 years. In most cases, they are associated with a viral infection such as otitis media or roseola. 

There are two types of febrile seizures. Simple febrile seizures are the most common type. They last from a few seconds to 15 minutes. Complex febrile seizures last longer than 15 minutes and may occur more than once within a 24-hour period. In some cases, they may affect just one side of the body. Although febrile seizures may frighten parents, they are typically relatively harmless. Still, a physician should be consulted after a child’s first febrile seizure or after any febrile seizure that lasts more than five minutes or that is accompanied by symptoms such as vomiting, breathing difficulties or extreme drowsiness.

Children with epilepsy also experience recurring seizures. In about half of all cases, a child outgrows the condition by adolescence if it is properly treated. Epilepsy may not affect intelligence or a child’s process of development.

Other causes of seizures in children include:

• Brain injuries. Lack of oxygen to the brain or trauma to the brain can result in seizures. A brain tumor can also lead to seizures.
  
  
• Infections. For example, the Shigella bacteria present in contaminated water or food can cause an infection that triggers seizures. Infections that cause meningitis can also trigger seizures.
  
  
• Poisoning. Drugs and chemicals such as cocaine, nicotine, pesticides, tricyclic antidepressants and certain types of mushrooms can also trigger seizures.
  
  
• Metabolic problems. Conditions such as low levels of glucose (e.g., caused by uncontrolled diabetes) in the body can cause a child to have a seizure.