Ok, now, coming back to amenorrhea.

好，现在说回到经。

A rarer cause of primary amenorrhea is androgen insensitivity syndrome.

导致经一个罕见因是雄激素不敏感综合征。

Finally, endocrine disorders can also cause primary amenorrhea.

最后，内泌疾病也会导致经。

The most common cause of secondary amenorrhea is pregnancy.

最可继经因是怀孕。

Which would explain why amenorrhea is most common among ballet dancers, gymnasts, and long distance runners.

这也解释为什麽经对芭蕾舞者 体操选手及长跑运动员来说很常见。

In females, primary sex characteristic dysfunction includes amenorrhea or absence of menstruation, or oligomenorrhea or irregular menstrual cycle.

在女中，第一征功障碍包括经，即无月经，或月经减少，即月经周期不规则。

Issues with the pituitary gland can also cause secondary amenorrhea.

垂体问题也会导致继经。

The most common cause of primary amenorrhea is Turner syndrome, where one X chromosome is either completely or partially absent.

最可经因是Turner综合征：有一个X染色体完全或者部缺失。

There are many causes of secondary amenorrhea, and when they occur before menarche, all of these can also cause primary amenorrhea.

有许多因会导致继经，而当它们在初潮前生时，都会导致经。

The one symptom of both primary and secondary amenorrhea is, well, the absence of menstruation.

和继经共有一个症状是没有月经。

Another condition that affects the hypothalamic-pituitary-ovarian axis and can be responsible for secondary amenorrhea is polycystic ovary syndrome.

另一种影响下丘脑-垂体-卵巢轴并可导致继经疾病是多囊卵巢综合症。

The first step when evaluating primary or secondary amenorrhea is to rule out pregnancy with a pregnancy test.

评估或继经第一步是用孕检排除怀孕可。

Sometimes though, menstruation either never starts which is called primary amenorrhea or suddenly stops in a person who's previously menstruating which is called secondary amenorrhea.

而有时，（青春期后）月经从未出现，这被称为经；或是先有月经周期，但突然停止，这就被称为继经。

All right, as a quick recap… amenorrhea is the abnormal absence of menstruation in females of reproductive age.

好！快速回顾一下：经指育龄期女无月经或月经异常停止。

When this happens, TRH also stimulates prolactin release - so hyperprolactinemia and amenorrhea occur.

与此同时，TRH也刺激泌乳素泌，所以也会出现高泌乳素血症和经。

Interestingly, hypothyroidism - a condition where there's low levels of thyroid hormones - can also cause amenorrhea.

有趣是，甲状腺功减退症，一种由于甲状腺激素合成及泌减少导致疾病，也可会导致经。

An early symptom is agalactorrhea, whereas late symptoms include amenorrhea, low blood pressure, low blood sodium, low blood glucose levels, as well as fatigue and muscle loss.

早期症状包括产后无乳，而晚期症状包括经、低血压、低血钠、低血糖、疲劳和肌肉萎缩。

With functional hypothalamic amenorrhea due to anorexia, there's significant weight loss and decreased bone density which can cause fractures.

由于厌食导致功下丘脑经患者往往减重过度且骨密度下降，易致骨折。

Primary amenorrhea is when a female hasn't had her first menstruation, called menarche, by age 16, despite normal growth and having started puberty.

经指女在16周岁前没有初次月经（即初潮），尽管生长育、进入青春期均无异常。

Later symptoms include amenorrhea, an absence of a normal menstrual cycle, even after a period of lactation, which is due to a lack of luteinizing hormone and follicle stimulating hormone.

晚期症状包括经，即月经周期不正常，甚至就在哺乳期后出现，这是由于缺乏黄体生成素和卵泡刺激素。