The first is carotid plaques. Many cerebral infarctions are caused by carotid plaques without active treatment, especially hypoechoic soft plaques or plaques with mixed echoes; The second is that high blood pressure is not well controlled, high blood pressure is unstable, and large fluctuations can easily lead to organ damage, and the brain is prone to cerebral hemorrhage or cerebral infarction; the third is atrial fibrillation. Attention, especially in the elderly, the incidence of atrial fibrillation is relatively high; the fourth is “H-type” hypertension, that is, patients with high blood pressure are accompanied by elevated homocysteine.