Stroke · the one thing most likely to happen to you卒中 · 中国人一生中最可能发生的那件事

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脑每分钟死 190 万神经元 · 缺血和出血是相反的两种病 · 别自行吃阿司匹林 · 半暗带决定时间窗 · 症状消失更要去急诊 · 十个因素解释九成风险

How badly the brain takes ischemia

Stop 1/6

脑子对缺血有多不耐受

Your brain is only 2% of your body weight, yet it eats about a fifth of all the oxygen and energy you use (Raichle 2002). It stores almost no fuel — when blood stops, it starts dying within minutes.

So when a brain artery blocks, time becomes an organ. Someone did the arithmetic: in a typical large-vessel ischemic stroke, left untreated, about 1.9 million neurons die every minute, along with 14 billion synapses and 12 km of nerve fibers (Saver 2006). Converted to another scale, the ischemic brain ages roughly 3.6 years per hour.

So *time is brain* isn't a slogan, it's a sum: every minute you hesitate is subtracted from the speaking, walking, and face-recognizing of the rest of your life.

The brain isn't entirely without backup. Small bypass channels run between arteries — collaterals; when the main road blocks, some blood still squeezes around. And blood flow doesn't fall to zero in one step: it crosses two thresholds in turn. First it drops below the level where neurons stop firing (which is when that side of your body stops obeying you), and only lower down does it cross the level where cells actually die (Astrup 1981). People whose collaterals reach land between the two thresholds, and are salvageable; people whose don't fall straight through. That's why the same blocked artery leaves one person nearly fine and another instantly paralyzed on one side.

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本站提供科普与一般性建议，不替代医师诊断或处方；有症状或正在服药请咨询合格医师。 Educational content, not medical advice — consult a clinician for diagnosis or treatment.

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