为什么你的头发不长了?

At one point or another, all of us have looked in the mirror and thought, "Ugh, why the hell won't my hair grow?" - but can hair really stop growing, or is it all in our inpatient minds?
某时某刻，我们所有人都会一边照着镜子一边想着，"哎，我的头发为什么就是不长了呢？"--但头发真的会不长吗？还是只是我们不够耐心呢？

While it's true that your hair probably hasn't stopped growing altogether, there are some factors that can slow the growth or make it seem like the growth has been stunted. We checked in with experts and they gave us this master info as well as some tips on how to help things along.
虽然你的头发可能还没有停止生长，但有些因素会拖慢头发的生长速度，就好像你的头发不长了一样。我们咨询了一些专家，他们向我们提供了专业信息和小建议，让我们的头发茂密生长。

Are you getting trims often enough?
你是不是经常修头发？

"Some women try to hang onto as much length as possible by avoiding haircuts, and yet they gain no length," says Shab Aghajani, Roy Teeluck Salon stylist. "We all have a maximum length our hair can reach according to our current regime. This is where your ends simply begin to break instead of continue to remain strong and healthy. Until you change your existing habits and products used on your hair, nothing will change about your hair. Trim the split ends, and use the right hair mask and treatment to nourish your hair, because clearly you've plateaued and nothing will change unless you make some changes yourself."
"有些女性总是不剪头发以尽可能的使头发长长，但实际却一点儿没长，"罗伊狄拉克美容院造型师Shab Aghajani说道。"根据现状，我们每个人的头发都有生长限度。所以你的头发会开始分叉，而非继续柔韧而健康。除非改变现在的习惯和护发产品，否则你的头发不会发生任何改变。修剪分叉的头发、使用正确的发膜和护发产品，可以滋养头发，因为很显然，你的头发已形成固定模式，除非你作出改变，否则什么变化都不会发生。"

Genetics
遗传

Whether we have pinpointed it or not, we all have an individual hair cycle growth phase in which their hair has potential to reach its longest.
无论我们是否曾明确指出，但我们每个人都有各自的头发生长周期，并且头发有可能长到最长长度。

"This does not mean that hair always stops growing once it reaches a specific length, but once a certain amount of time has passed. The growth phase is largely determined by genetics and typically lasts between two and six years," says Dr. James C. Marotta, plastic surgeon and hair restoration specialist.
"这并不意味着头发长到一定长度就会不长了，但一旦特定时间过去了，头发就会停止生长。生长阶段主要受遗传影响，通常持续2至6年，"整形医生和头发修复专家詹姆斯· C· 马罗塔医生说道。

Age
年龄

Aging brings with it a host of life complications, not the least of which is our hair. As we get older, chances are our hair is weaker. Years of heat styling and bleaching can build up to create major damage.
衰老会带来一系列的生命并发症，其中最重要的就是我们的头发。当我们年纪越来越大，我们的头发就会越来越弱。长年烫发、漂染都会对我们的头发造成重大损伤。

"Studies have shown that the biology of hair can change and the growth stage may shorten. This means that hair could begin shedding faster, making it appear thinner and shorter," says Marotta. "For instance, if you have a five-year anagen (growing) period, a single strand of hair will continue growing for five years before it will go into 'resting' phase. "
"研究已表明：头发的机理会发生变化，生长阶段可能缩短。这就是说我们的头发会脱落得更快，因此会更薄、更短，"马罗塔说道。"例如，如果你的头发生长阶段是5年，那你的头发在进入'休息'阶段前，还会继续生长5年。"