听力文摘：为尿床"平反"（在线收听）

Never a happy topic, bed wetting is a very distressing problem for five to seven million American kids. If we can’t explain why some people like to pick on these kids, can we at least shed some light on what causes bed wetting?

尿床可是个不愉快的话题。尿床困扰着500万至700万名美国儿童。如果我们无法解释为什么偏偏这些儿童尿床，那么我们至少探究下尿床的原因吧！

At one time, people punished bed-wetters for acting badly, but today scientists believe that this condition has several physical causes. Some kids suffer from problems like infections or anatomicaldefects that can be easily identified and treated.

以前，经常尿床的儿童会被罚。但是，如今科学家相信尿床是基于生理因素。一些儿童患常见可治愈传染病或结构缺陷。

Other causes are harder to pin down. One promising area of research is on the kidneyhormoneADH. We all produce more ADHhormone at night. ADH signals the kidney to slow down production. This is why we don’t go to the bathroom for eight hours at night but could never last that long between bathroom breaks during the day. Some children who wet their beds do not produce enough ADH at night. When given drugs that boost this hormone, they stop bed wetting.

其它原因就很难下定论了。有种可行性研究的方向是肾脏激素：抗利尿激素。夜晚人体分泌的抗利尿激素较多。抗利尿激素向肾脏发出减慢新陈代谢的信号。这是为什么我们夜晚八小时不上厕所，但是白天上厕所的间隔时间却更短。一些儿童尿床是因为夜晚没有分泌足够的抗利尿激素。服用药物促进抗利尿激素分泌就可以治疗儿童尿床。

Finally, some kids simply have small bladders and an undeveloped nervous system. The good news is that these kids, like most bedwetters, will grow out of it as their bodies develop and mature.

另外，有些儿童尿床仅仅是因为膀胱小且神经系统发育不完善。可喜的是随着身体机能的发育和成熟，大多数尿床儿童不再尿床。