Drowsiness after a seizure can be caused by medications, excessive physical exertion, and low oxygen. 1. Drugs: most of the anti-epileptic drugs are given during seizures, such as carbamazepine, phenytoin sodium, diazepam, etc. Anti-epileptic drugs usually have a sedative effect, which can lead to drowsiness. 2. Excessive physical exertion: when epileptic seizures occur, due to muscle spasms and abnormal contractions, they are extremely physically demanding and require sufficient rest to restore physical strength, so the duration of sleep after a seizure will be prolonged. 3. Hypoxia: due to excessive spasms lead to a state of relative hypoxia, resulting in blood and oxygen supply obstacles to the tissues of the brain, cerebral edema, so it leads to mild consciousness disorders and drowsiness. However, other factors can not be ruled out, if the patient has other discomforts, it is recommended to consult the doctor in time, and the doctor will give targeted treatment.