But more than that may cause nervousness, rapid heartbeat, palpitations, sleeplessness, and irritability.

但是再多就会导致神经过敏、心跳加快、心悸、失眠、和烦躁。

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Of course, too much caffeine can cause restlessness, anxiety, irritability, tremors, sleeplessness, headaches, gastrointestinal symptoms and abnormal heart rhythms.

当然，过多的咖啡因会导致烦躁、焦虑、兴奋、震颤、失眠、头痛、胃肠道症状以及不规律心律等等。

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People who suffer trauma may exhibit irritability, sleeplessness, and difficulties concentrating.

遭受创伤的人们可能会表现出易怒、失眠以及注意力集中障碍。

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Depressive symptoms are not simply feeling miserable, but can include feelings of fear, loneliness irritability or lack of concentration, and even sleeplessness.

BBC: Depression may boost heart risk