Usually, foaming at the mouth is due to the following reasons: 1. The most common cause is epilepsy, which can lead to foaming at the mouth during seizures, tonic clonic seizures, and grand mal seizures. 2. Acute cerebrovascular accidents, such as acute stroke, acute cerebral embolism, acute cerebral infarction, cerebral hemorrhage, etc., can also cause foaming at the mouth, accompanied by twitching of the limbs. 3. In the case of poisoning, such as organophosphorus poisoning or sedative drugs, foaming at the mouth may occur. 4, for newborns and children, often in the case of febrile convulsions or neonatal pneumonia, there is foaming at the mouth.