Common causes of sudden epilepsy include genetic factors, encephalitis, intracranial lesions, and cerebrovascular disease. The causes are different for different groups of people and need to be analyzed on a case-by-case basis. Most of the epilepsy is related to genetic factors, and the patient may be seizure-free for a long time, and the first seizure will give the impression of having the disease suddenly. In adolescents, the main cause is encephalitis or meningitis. Immediately after the onset of the disease, cerebrospinal fluid examination should be carried out in the Department of Neurology, or cranial magnetic resonance imaging, to clarify the diagnosis and then take standardized treatment for the cause of the disease. If there is cerebral edema and increased intracranial pressure, the intracranial pressure should be lowered to reduce cerebral edema. For the elderly, it is mainly caused by intracranial space-occupying lesions and cerebrovascular disease. The diagnosis is mainly clarified by cranial CT or MRI at the onset. If it is intracranial occupational lesions, the patient should be evaluated and conservative treatment or surgery should be chosen according to the condition. If it is cerebrovascular disease, symptomatic treatment should be taken for the condition, commonly such as thrombolysis. Epilepsy is a clinical syndrome caused by highly synchronized abnormal discharges of neurons in the brain, and is a neurological disease with sudden, transient, repetitive and stereotyped causes. Excessive stress, lack of sleep, irregular diet and alcoholism in life can all lead to epilepsy. If symptoms of epilepsy appear, you should go to the hospital for treatment.