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

这也能解释为什麽闭经对芭蕾舞者 体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.

在女性中，第一性征的功能障碍包括闭经，即无月经，或月经减少，即月经周期不规则。

The most common cause of secondary amenorrhea is pregnancy.

最可能的继发性闭经原因怀孕。

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

有趣的，甲腺功能减退症，一种由于甲腺激素合成及分泌减少导致的，也可能会导致闭经。

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

原发性和继发性闭经共有的一个症没有月经。

Ok, now, coming back to amenorrhea.

好，现在说回到闭经。

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

另一种能影响下丘脑-垂体-卵巢轴并可能导致继发性闭经的多囊卵巢综合症。

Finally, endocrine disorders can also cause primary amenorrhea.

最后，内分泌也会导致原发性闭经。

A rarer cause of primary amenorrhea is androgen insensitivity syndrome.

导致原发性闭经的一个罕见原因雄激素不敏感综合征。

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

由于厌食导致的功能性下丘脑性闭经患者往往减重过度且骨密度下降，易致骨折。

Issues with the pituitary gland can also cause secondary amenorrhea.

垂体的问题也会导致继发性闭经。

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

有一个X染色体完全或者部分缺失。

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

有许多原因会导致继发性闭经，而当它们在初潮前发生时，都会导致原发性闭经。

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

原发性闭经指女性在16周岁前没有初次月经（即初潮），尽管生长发育、进入青春期均无异常。

If the cysts are the result of polycystic ovary syndrome, you might also see amenorrhea and hirsutism, or excessive hair growth on the chin and upper lip, chest, and back.

如果囊肿由多囊卵巢综合征导致，可能会有闭经和多毛等症；多毛即下巴、上唇、胸、背等处有过多毛发生长。

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.

晚期的症包括闭经，即月经周期不正常，甚至就在哺乳期后出现，这由于缺乏黄体生成素和卵泡刺激素。

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

评估原发性或继发性闭经的第一步用孕检排除怀孕可能。

Next, there’s functional hypothalamic amenorrhea, which is when there is a decrease in GnRH secretion, leading to low levels of LH, FSH, and estrogen.

其次功能性下丘脑性闭经，即由于GnRH分泌下降导致LH、FSH和雌激素水平下降。

Now, sometimes secondary amenorrhea can occur because of premature ovarian failure - which is when the ovarian follicles undergo accelerated atresia and get depleted before the age of 40, resulting in early menopause.

有时，继发性闭经的原因卵巢早衰，即当卵巢滤泡加速闭锁，在40岁前消耗殆尽，造成提前绝经。

Primary amenorrhea is also suspected when a female hasn’t had menarche by age 13 and doesn’t show signs of puberty, which include developing secondary sexual characteristics like breasts.

当女孩13岁时没有初潮，且没有出现青春期发育征兆，也要考虑否为原发性闭经；青春期发育指第二性征发育，如乳房发育。