Secondary epilepsy belongs to one of the many types of epilepsy, causing more serious harm to the human body, and the specific causes of secondary epilepsy are as follows: 1, congenital and developmental disorders: including congenital malformations such as cerebral penetrating malformations, hydrocephalus, and other fetal infections, as well as developmental anomalies, such as tuberous sclerosis, facies atrophicus, and so on; 2, traumatic injuries: birth injuries, as well as brain infections, poisoning, and thrombosis during infancy, may also leave localized lesions in the brain, which gradually form epileptogenic foci. Craniocerebral injury in adults is also one of the important causes of epilepsy, which is called traumatic epilepsy; 3. Infection: all kinds of brain infections, including bacterial, viral, fungal and parasitic encephalitis, brain abscess or granuloma, can lead to epileptic seizures; 4. Tumor: slower-growing tumors, such as glioblastoma, astrocytoma, and meningioma, etc., especially those whose sites are close to the cerebral cortex, have a higher possibility of epileptogenicity; 5, Vascular disease: epilepsy produced after cerebral artery thrombosis and cerebral hemorrhage, usually seen in elderly patients; 6, degenerative diseases: degenerative diseases in childhood, such as progressive myoclonic epilepsy, diffuse periaxial encephalitis, etc., mostly presenting epileptic seizures; 7, metabolic disorders: severe systemic metabolic disorders, such as hypoglycemia, hypocalcemia, lipodystrophy, and water intoxication, etc., can also produce epilepsy.