The recurrence rate of stroke is very high and the causes are very diverse because the most common cause of stroke itself is atherosclerosis, and there are more risk factors and diseases associated with atherosclerosis. For example, diabetes, hypertension, dyslipidemia, increased homocysteine, obesity, smoking, and alcohol consumption. These are all long-term risk factors that cause atherosclerosis to worsen and develop to a certain extent to atherosclerotic plaques, which then block the blood vessels and cause infarction. Or the plaque falls down and blocks the distal blood vessel causing infarction. Since there is the first occurrence of the disease, it means that there is already a basis for the lesion, and the existence of this basis for the lesion can occur at any time. Moreover, the closer to the first stroke, the higher the tendency of recurrence, the possibility of recurrence or the risk of recurrence. Once stabilized at a later stage, the risk of recurrence is relatively low after 1 year. Therefore, the cause of stroke recurrence is also related to the underlying disease and atherosclerosis. If the atherosclerosis is not well controlled, the related diseases and risk factors are not well controlled and recurrence will occur. For example, if the patient continues to smoke or drink, if diabetes is not well controlled, if hypertension is not well controlled, if there is no treatment for arterial protection, if statins are not used, if there is no antiplatelet therapy, if the patient has heart disease or atrial fibrillation, and if there is no anticoagulation therapy, there will be a recurrence. Therefore, to prevent recurrence, it is necessary to know what causes stroke and what are the related risk factors, to treat the related risk factors and the cause, and to provide long-term reasonable treatment to effectively prevent recurrence.