脱发的原因（翻译）

发之家

脱发是一个同时困扰着男性和女性的普遍问题。一般来讲，男性更容易出现脱发症状，脱发往往给人们带来失去自信等消极影响，相信我们再了解了脱发的缘由之后，能够更加理性和正确的看待脱发问题。

最常见的脱发是“雄性秃”，它会使你的头发逐渐稀疏，并最终产生脱发。其最坏的情况是出现“普秃（全身毛发均脱落）”，老年人的脱发现象尚属正常，但仍然有一些人在青年时候即产生了脱发现象。

人们一般认为脱发是因为来自母方的遗传，但这方面遗传影响的概率大概只有50%。事实上，引起脱发的因素很多，比如你暴露在了化学物质、有毒物质中或者接受了如化疗之类的特殊治疗等。压力方面的问题，如情绪创伤、沮丧也是引起脱发的原因之一。
头皮上过多的油脂分泌物以及不健康的饮食习惯和生活方式也肯能会引起脱发，如果一个人长期食用高脂类食物，从中摄取大量的卡路里也肯能导致早期头发。

脱发也可能是某些疾病症状之一。这种类型的脱发与普通由年龄增长引起脱发有很大不同，也很少会是这类疾病先发或者唯一的表现症状。会引起脱发症状的疾病通常有：甲状腺机能减退、缺铁、脂谥性皮炎和二期梅毒疹，这种由疾病引起的脱发也会在这些疾病被治愈后消失，到时你的头发就会回到正常的生长状态。

还有两种类型的脱发：牵引创伤性脱发和拔毛发症。牵引创伤性脱发一般归咎于头发受到过度和慢性的拉拔，在喜欢给自己头发编辫子或打结的人群中较常见。这也是为什么部分锡克人常常会经历脱发的原因，他们终生不剪头发，成年锡克男子一般都将头发用布层层围起，绕成一个像“大磨盘”的头包，这种对头发频繁的拉拔导致了牵引创伤性脱发。

拔毛症则是对健康头发的故意拉拔，这情况通常具有由临时性，或者是由精神或感情类问题引起的，常见于有拉自己头发、吮吸手指的习惯小孩子之中。
Hair loss is a very common problem that affects both men and women, from all parts of the world. Men are more prone to hair loss, and with the onset of hair loss, some people tend to lose some self confidence. However if and when the causes of hair loss are understood, it is possible to handle the problem much more efficiently.

The most common type of hair loss is androgenic alopecia which is a gradual thinning of hair, which culminates in hair loss. Its extreme form is alopecia universalis where there is total hair loss over the body. Although it is normal to lose hair in old age, some men experience hair loss during puberty.

It is generally thought that hair loss is an inheritance from the maternal side; however chances of such an inheritance are 50%. The actual causes of hair loss are varied and may range from anything like exposure to chemicals, poisons and some medical treatments like chemotherapy. Stress is also another reason for hair loss which may include emotional trauma and depression.

Even the growth of tumors and other types of outgrowths in the skin lead to hair loss. An unhealthy diet and lifestyle also tends to provoke hair loss. This means that a person following a sedentary lifestyle with a high fat diet with high calorie intake can lead to early hair loss.

Some diseases have hair loss as one of their symptoms. Such hair loss is usually vastly different from the normal hair loss that is associated with aging and is seldom the first and only symptom of these diseases. Some diseases associated with hair loss are hypothyroidism, iron deficiency, seborrheic dermatitis and secondary syphilis. Once these diseases are treated, hair grows back to its normal style.

There are also two other types of hair loss patterns; traction alopecia and trichotillomania. In traction alopecia, hair loss is due to excessive and chronic pulling of the hair which is more prevalent in people who braid or knot their hair. This is why Sikh men experience such hair loss - their beard hair is pulled straight and twisted and tightly knotted. It is this daily knotting that leads to traction alopecia.

In the case of trichotillomania, it is the intentional pulling of healthy hair. This is usually a temporary, psychiatric or emotional problem. It is most prevalent in children where the pulling of strands of hair is associated with thumb sucking and other habits.

ankang

分析的很实在，我就是甲状腺机能减退和脂谥性皮炎

ejiamm

这个翻译好长啊

普罗旺斯的眼泪

分析的很科学  莫大的感谢