The precursors of cerebral infarction include dizziness, blackout, weakness, blurred vision, numbness of limbs, crooked mouth and eyes, and speech disorders. If drooling in sleep occurs suddenly, the possibility of cerebral infarction cannot be ruled out. Cerebral infarction is also known as ischemic stroke, mostly seen in middle-aged and elderly people, with hypertension, diabetes, smoking and other risk factors, often in the quiet or sleep onset, part of the patient can have a history of transient ischemic attack. Clinical manifestations mainly depend on the location and size of the infarct foci, as well as the ability of cerebrovascular collateral circulation, which can be manifested as limb numbness, weakness, impaired consciousness, etc., and also facial paralysis, crooked mouth, and sudden drooling in sleep, with focal signs reaching a peak more than 10 hours or 1-2 days after the onset of the disease. If the phenomenon of sleep drooling suddenly appears, please go to the hospital in time.