A seizure occurs when the brain suddenly experiences an uncontrolled burst of electrical activity. This usually happens after a head injury or stroke, but sometimes even a severe infection, such as meningitis, viral encephalitis, malaria, or chickenpox, can cause seizures. A seizure episode can often last about 30 seconds to two minutes, during which a person might experience several symptoms, including changes in behavior, emotional health, and consciousness levels.

Common causes of seizures
Nerve cells or neurons send electrical signals to the different areas of the brain.

• Provoked seizures
  They are also known as nonepileptic seizures and are generally a result of a temporary health condition that irritates the brain. They can even result from certain circumstances or poor lifestyle habits, such as not getting proper sleep for a prolonged period.
• Unprovoked seizures
  These seizures generally occur randomly and spontaneously and more often than provoked seizures.
• Idiopathic seizures
  When a seizure’s cause is unknown, it is called an idiopathic seizure.
• Psychogenic non-epilepsy seizure (PNES)
  Epilepsy is a health condition where the nerve cells do not work properly, causing seizures. Sometimes, a person can have seizures that appear similar to those that occur with epilepsy. But instead of abnormal brain activity, the seizures result from severe, intense physical or emotional stress. When that happens, the condition is called PNES.

While every type of seizure may have a unique underlying cause, they also share certain common triggers.

• Abnormal levels of blood sugar
• Effects of certain kinds of treatment
• Exposure to flashing and flickering lights
• Health conditions caused by overheating, such as heat rash, cramps, strokes, or exhaustion
• Severe and high fever
• Sleep deprivation
• Prolonged stress

Typically, the triggers differ from one person to the next. If someone experiences several episodes of seizures due to different triggers, they should monitor their condition and symptoms. This information allows a healthcare provider to determine an accurate diagnosis and treatment plan.

Risk factors of seizures
Although a seizure can occur at any age and affect anyone, certain factors increase one’s chances of the condition.

• Preexisting and underlying medical condition
• Biological family history of seizures
• Age below 18 years
• Age above 50 years

Some health conditions make a person more prone to seizures.

• Aneurysms
• Tumors in the brain
• Cerebral hypoxia
• Cerebrovascular disease
• Diabetes
• Severe traumatic brain injury or concussion, especially the ones that cause loss of consciousness
• Alzheimer’s disease, frontotemporal dementia, and other types of degenerative brain diseases
• Eclampsia
• Low levels of sodium (hyponatremia), calcium, or magnesium, and other problems related to electrolyte levels in the body
• Epilepsy
• Genetic conditions like Dravet syndrome or Lennox-Gastaut syndrome

Sometimes, seizures also occur as a symptom or effect of other health-related problems.

• Hormone-related changes
• Infections like encephalitis, meningitis, or sepsis
• Inflammation caused by autoimmune health conditions
• Congenital brain abnormalities
• Strokes
• Exposure to toxins and poisons like carbon monoxide or heavy metals
• Venomous bites or stings

Symptoms of seizures
Usually, the symptoms differ based on the severity and type of seizure. That said, certain symptoms are common across all cases and can be easily detected.

• Sudden loss of consciousness
• Random onset of convulsions, muscle spasms, jerking, or other uncontrollable movements
• Stiffness in the arms and legs, sometimes when a person is asleep
• Inability to breath
• Sudden loss of muscle strength, causing a risk of fall
• Unconsciously staring at a distance with a loss of awareness of the surroundings
• Feeling confused, fearful, joyous, anxious, or experiencing other emotional changes
• Clenching the teeth too tightly
• Unconsciously drooling
• Sudden abnormal eye movements
• Involuntary loss of bladder or bowel control
• Making noises such as snorting and grunting

These symptoms usually do not last more than a few seconds or minutes, meaning they are temporary. But i n some cases, the symptoms of a seizure are not quite evident. In such situations, it is helpful to watch out for certain other warning signs that might indicate that an episode of seizure may occur. While not everyone develops the warning signs, knowing them is especially important for those at high risk of the condition. It can help to take proactive measures to minimize the intensity of the seizure and avoid any injuries.

• Overstimulation of the senses
  If lights suddenly appear brighter and objects in the surroundings appear distorted, it might indicate an impending seizure episode. One might also hear unexpected sounds or experience sudden unexpected tastes, such as metallic taste or bitterness in the mouth. Strange smells and strange feelings on the skin, like numbness or tingling, may also occur.
• Emotional changes
  A sudden onset of strong emotions such as fear or joy may occur without any reason. Sometimes, one might also experience déjá vu, i.e., when a new experience feels quite familiar, or jamais vu, i.e., when a familiar experience begins to feel new.
• Autonomic signs
  Signs like sweating, making too much saliva or drooling, noticing pale skin, or getting an upset stomach result from bodily processes that the brain automatically controls.