Epilepsy: This is the most common cause of seizures, characterized by recurrent, unprovoked seizures due to abnormal electrical activity in the brain. The likelihood of epilepsy as a diagnosis increases with the number of seizures a patient experiences.

Head Trauma: Traumatic brain injuries can cause seizures, either immediately after the injury or as a long-term consequence. The mechanism involves damage to brain tissue that disrupts normal electrical activity.
Infections (Meningitis, Encephalitis): Central nervous system infections can lead to seizures due to inflammation and disruption of brain tissue.
Stroke or Transient Ischemic Attack (TIA): Both ischemic and hemorrhagic strokes can cause seizures, either at the onset or as a complication. The seizures are thought to result from the sudden change in brain tissue perfusion and the subsequent injury.
Metabolic Disorders: Conditions like hypoglycemia, hyponatremia, and hypernatremia can precipitate seizures by altering the brain's electrolyte balance and energy supply.
Drug or Alcohol Withdrawal: Withdrawal from certain substances, notably alcohol and benzodiazepines, can lead to seizures due to the brain's adaptation to the constant presence of these substances and the subsequent rebound effect upon their removal.

Subarachnoid Hemorrhage: Although less common, this condition is critical and potentially fatal. Seizures can be an initial presentation of a subarachnoid hemorrhage, especially if the bleed is near the cerebral cortex.
Brain Tumors: Both primary and metastatic brain tumors can cause seizures by irritating the surrounding brain tissue.
Central Nervous System Vasculitis: Inflammation of the blood vessels in the brain can lead to seizures, among other neurological symptoms, and requires prompt treatment to prevent further brain damage.
Intracranial Hemorrhage: Similar to subarachnoid hemorrhage, other types of intracranial hemorrhages (intracerebral, epidural, subdural) can cause seizures and are medical emergencies.

Autoimmune Encephalitis: A group of conditions characterized by an immune response against components of the brain, leading to inflammation and seizures.
Mitochondrial Disorders: Genetic disorders affecting the mitochondria, such as MELAS syndrome, can cause seizures as part of a broader spectrum of neurological and systemic symptoms.
Parasitic Infections (e.g., Neurocysticercosis): Infections like neurocysticercosis, caused by the pork tapeworm, can lead to seizures by forming cysts in the brain that irritate surrounding tissue.
Hashimoto's Encephalopathy: A rare condition associated with Hashimoto's thyroiditis, characterized by seizures, among other neurological symptoms, and responsive to corticosteroid treatment.