The last few articles have talked about the basics of stroke and you have a preliminary understanding of it. As we all know, age is an important risk factor for stroke, and it is generally feared after the age of 50. Nowadays, due to the high work pressure and fast pace of life, cerebrovascular disease and stroke are no longer the “patent” of the elderly, and the incidence of ischemic stroke among young people has been on the rise recently. Many young patients often think that they are young, even if their blood pressure is high, it is not a problem, so they do not seek medical advice or take medication, coupled with smoking, drinking and staying up late, it is easy to have a stroke. Youth stroke is a stroke that occurs in young people under the age of 35. Epidemiological findings show that youth strokes account for about 10% of all strokes, mainly ischemic strokes, with a male predominance. Xiao Jiang is a happy mother, 33 years old, her son is well behaved, her husband is considerate, and the whole family is very healthy and rarely goes to the hospital. However, 6 days ago in the afternoon, Xiao Jiang suddenly had a headache, followed by 5 hours later a significant dizziness, shaky eyes, unstable walking, while vomiting 5-6 times, diarrhea 2 times, measured body temperature 37, 4 ℃, went to the nearest hospital emergency, given static medication (specific unknown) after the dizziness symptoms continue not to improve, the night sleep is poor. In the afternoon of the following day, the dizziness and headache improved significantly, but there was still a feeling of unsteadiness in walking, and the cause was not identified, so he was referred to our hospital. Based on our previous clinical experience, we first considered whether it was an intracranial infection, and repeatedly asked for a history of no pre-morbid infection and only a transient hypothermia on the day of onset. When the diagnosis was at a loss, her cranial MRI results surprised me even more: there were multiple abnormal signals in the bilateral cerebellar hemispheres and the right part of the brainstem, with long T1 and long T2, FLAIR high signal, consistent with the manifestation of acute or subacute infarction. To first rule out intracranial infection, a lumbar puncture was performed on the next day of admission, and cerebrospinal fluid pressure, routine, biochemistry, and cytology were normal. No significant abnormalities were found in the three major routine, viral series, thyroid function, homocysteine, rheumatoid factor, ASO, CRP, thyroid ultrasound, and chest CT on admission. The patient was not pregnant and had no history of taking birth control pills. The lesion characteristics and distribution were not consistent with demyelinating manifestations such as multiple sclerosis, infection had been excluded, and infarction was still considered without risk factors for atherosclerosis, then cardiogenic factors should be excluded below. After completion of viral series and barium meal fluoroscopy, the patient underwent transesophageal cardiac ultrasound and right heart acoustic angiography, which showed normal cardiac structure. During right heart acoustic angiography, sparse contrast echoes were seen in the left atrium and left ventricle after performing a wah maneuver and continuous coughing, suggesting that the foramen ovale was not closed. Another 34-year-old male patient was newly married for 1 month. After a drinking session, frequent and violent vomiting occurred, and hemiparesis of the right limb with muscle strength of grade 0 occurred the next day, and he came to the hospital in an emergency. The cranial MR examination showed multiple ischemic infarct foci in the left cerebral hemisphere, and the cause was still not found after the tests that could be performed in our hospital to cause cerebral infarction (vascular origin and cardiac origin). After careful follow-up of the medical history, the patient did not eat enough on the day of drinking, and the vomiting lasted for a long time (almost 1 night) and was frequent, without timely replenishment of water loss, and was finally diagnosed with multiple cerebral infarcts caused by cranial hypoperfusion due to blood volume deficiency. The patient’s muscle strength of the right limb basically returned to normal on the 5th day after admission. It is easy to see from the above two cases that there are various causes of ischemic stroke, and when it occurs in young and middle-aged people, it is often misdiagnosed or missed. Today, we would like to summarize the common causes of ischemic stroke in young people in order to prevent it before it happens. The main cause of stroke is atherosclerosis, which is the first and foremost factor. The main cause of stroke in young people is atherosclerosis. This is associated with an increasing number of young people with abnormal lipid metabolism, hypertension, diabetes, obesity, smoking, high work stress and high calorie diets. Recent data from Europe and the United States show that atherosclerosis accounts for 8-17% of strokes in young people, but in China the proportion of strokes in young people due to this cause is higher, and 60% of intracranial stenoses in people under 35 years of age are due to atherosclerosis, with about one-third of these patients having no risk factors. There are also non-atherosclerotic causes, such as: 1. Arterial entrapment: Trauma is the most common cause of aneurysms in the entrapped neck vessels. Cervical vessel entrapment has a high risk of embolus formation. 2, Moyamoya disease: The mechanism is unclear; some cases are congenital, but it may also be related to acquired factors, such as trauma, and a portion of young Moyamoya is associated with atherosclerosis. The clinical presentation of patients varies widely. The disease should be considered in pediatric and young patients with recurrent unexplained transient ischemic attacks, cerebral infarction, cerebral hemorrhage, and subarachnoid hemorrhage without evidence of hypertension or atherosclerosis in clinical practice. 3. Inflammatory diseases: Takayasu arteritis, for example, is a chronic, progressive, nonspecific inflammatory disease involving the aorta and its major branches as well as the pulmonary arteries, mostly in young women. The cephalobrachial artery type causes varying degrees of ischemia mainly in the brain and upper extremities. Severe cerebral ischemia may be associated with recurrent syncope, convulsions, aphasia, hemiparesis, or coma. Another important cause of stroke in young people is cardiogenic emboli. Emboli usually arise from structural lesions of the heart and are commonly associated with: 1. heart valve disease and endocardial lesions: mitral stenosis, prosthetic valves, and infective endocarditis 2. arrhythmias: atrial fibrillation is the most common and can also be seen in sick sinus syndrome. 3. Ovular foramen insufficiency: It accounts for a large proportion of cardiogenic strokes in young people, and retrograde emboli from the venous system can enter the arterial system directly through the right-to-left shunt channel, causing cerebral embolism. 4. Cardiac mucinous tumor: more common in women. The possibility of cardiac mucinous tumor should be considered in young ischemic stroke patients without evidence of cerebrovascular disease, especially sinus rhythm, extensive facial freckling, and endocrine hyperactivity; especially in young women with unexplained peripheral neuropathy with vascular occlusion and inflammatory signs and negative autoantibodies. There are also less common causes of ischemic stroke in young people, such as antiphospholipid syndrome, hyperviscosity, protein C and protein S deficiency, migraine, oral contraceptives, and hypoperfusion. In addition to atherosclerosis, which can be a clear risk factor, it is important to know the other common causes of stroke in young people. The acute mortality rate of stroke in young people is about 1-7%, which is lower than that of older patients, but it may still leave serious disability and seriously reduce the quality of survival in the long term. In young stroke patients, the focus should be on comprehensive examination to find the cause and specific treatment for the cause, especially for systemic diseases with concomitant systemic manifestations, and after the acute phase of stroke is stabilized, collaboration and communication with other departments should be emphasized to provide comprehensive and systematic treatment for the cause. In principle, the treatment is basically the same as that for middle-aged and elderly patients. In the recovery period, controllable risk factors should be actively controlled to prevent recurrence.