Even if the stone do not cause any pain, it needs to be removed since it can cause kidney failure and permanent kidney damage.

即使石头没有造成任何疼痛，它需要被删除，因为它可导致肾功能衰竭和永久的肾脏受损。

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This can be mild, however, in some cases it can lead to epileptic fits, permanent kidney failure and even death.

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