Drooling may be the precursor of cerebral thrombosis, but it may also be caused by other factors such as oral diseases and facial nerve palsy. The precursor symptom of patients with cerebral thrombosis is transient ischemic attack, which can be manifested as salivation at the corners of the mouth, unfavorable speech, numbness and weakness of one side of the limbs, etc., and can be recovered on its own in a short period of time. However, other diseases can also lead to salivation, such as the elderly with age, tooth loss after the corner of the mouth closure is incomplete, there will be salivation at the corners of the mouth. And facial neuritis caused by peripheral facial paralysis, one side of the facial nerve paralysis, one side of the facial muscle relaxation, will also appear in the corners of the mouth salivation phenomenon. If there is salivation at the corners of the mouth, you should go to the regular hospital to find a doctor to do a neurological examination, to make a clear diagnosis, and timely treatment for the primary disease.