脱发对很多人来说都是一个敏感的话题。尽管生活中特定的事情和变老可导致脱发，但是有时候一种健康问题可导致脱发。这个问题就是斑秃。斑秃是一种会导致你的头发比正常情况下脱落得更多的状况。

Hair loss can be a sensitive topic for a lot of people. While certain life events and old age can lead to hair loss, sometimes it can be caused by a health condition. One such condition is alopecia areata.Alopecia areata is a condition that can cause your hair to fall out more than normal.

The average person can pretty easily lose up to around 100 pieces of hair a day from their scalp, with most of that growing back. Alopecia areata is when that hair loss gets more significant and you have trouble getting that hair to grow back. The amount of hair that falls out varies from person to person, but it can be anything from small, rather unnoticeable patches, to greater amounts of hair loss as the patches increase in size and connect with each other.

We often think of this as hair loss relating to what's on top of your head, but this condition can also include hair loss in places like your eyebrows and eyelashes, as well as your face and other parts of your body.

According to the National Alopecia Areata Foundation, this condition is fairly common,affecting as many as 6.8 million Americans with a lifetime risk of 2.1%. While there is no cure, symptoms can come and go. It might develop slowly, then go away for a few years before coming back. Alopecia areata can lead to alopecia totalis, where you lose all of the hair on your scalp, or alopecia universalis, where you have total hair loss.

Generally, when and if your hair ever does grow back, it might fall out again later on. It often first shows up with children, but can begin in any age group. So why does any of this happen? To answer that, we gotta take a look at your immune system.

Alopecia areata usually develops as a result of your immune system attacking your hair follicles, which ultimately results in hair loss. In this way, alopecia areata is considered an autoimmune disorder.

That puts it in a group of other conditions like rheumatoid arthritis, type 1 diabetes, and Graves' disease. Autoimmune disorders are basically when your own body ends up attacking itself, leading to an often chronic condition where symptom management is the main treatment.

When it comes to alopecia areata, treatment can include things like topical agents that you rub into the affected area and steroid injections to help stimulate hair growth. A study that came out in 2015 reported that excimer lamps could be an effective treatment for alopecia areata, especially in people with severe cases.

In this study, they found that patients who received treatment with a 308-nm excimer lamp began to see improvements after 2 months. Only mild side effects were noted, suggesting that the excimer lamp could be a safe alternative treatment for people with alopecia areata.

Alopecia areata isn't the only thing that can cause hair loss though. Medical conditions like thyroid diseases or scalp infections can do it too.

Hormonal changes can lead to temporary hair loss, like with pregnancy or menopause.