Stroke is a very serious cardiovascular disease, so prevention is important. There are some signs and symptoms before the onset of stroke, so it can play a role in timely prevention and treatment. So what are the precursors of stroke? 1, momentary blackness: suddenly appear in front of the eyes, a few seconds later can recover, not accompanied by nausea, vomiting, impaired consciousness and limb paralysis. This is caused by reduced intracranial blood flow or tiny blood clots passing through the retinal artery. Because, the ophthalmic artery is the first branch of the carotid artery and is the most sensitive to carotid artery sclerosis, stenosis and ischemia, so the black mask can be regarded as the earliest alarm signal of stroke. 2. Transient visual impairment: Blurred vision or visual field defects with paroxysmal episodes, mostly recovering on their own within an hour. This is the result of occlusion of the central retinal artery or branch arteries caused by reduced cerebral blood flow, but no cerebral neurological signs have yet appeared, which can be regarded as an early stroke forecast signal. 3, frequent yawning: This is the result of progressive aggravation of cerebral arteriosclerosis, narrowing of the lumen, and increasing cerebral ischemia and hypoxia. According to statistics, within 5 to 10 days before the onset of ischemic stroke, up to 80% of people yawn frequently. Therefore, do not ignore this signal. 4, twisted neck hand numbness: mostly occurs when the head turned to the side shaving, suddenly feel finger weakness, razor to the ground, some speech unclear, 1 to 2 minutes to recover. This is because when turning the head, causing the already hardened carotid artery twist, aggravating the results of the narrowing. This phenomenon is enough to warn people that stroke can occur at any time. 5. Transient ischemic attack: That is, there is a transient hemiparesis or monoparesis, possibly accompanied by aphasia, but of short duration, mostly recovering completely within 24 hours, which indicates that there has been a mild stroke. It can be taken as a precursor to a progressive or complete stroke. 6. Condition: Severe or surge blood pressure fluctuations, increased headache and dizziness and tinnitus, nervousness or drowsiness in the elderly indicate the possibility of hemorrhagic stroke. Anyone found to have one of the above signs must go to the hospital for early examination, including blood rheology test, cardiovascular ultrasound, cerebral blood flow, fundus and CT examination, etc. Even if the test results do not reveal any changes in the disease, preventive treatment measures should be taken under the guidance of a doctor.