为何现在患自身免疫性疾病的人越来越多? 各种过敏，比如花粉过敏也算吧？

自身免疫性疾病，免疫系统倾向于产生抗体，而不是抵抗感染，而是攻击健康的细胞和组织。

• Autoimmune disease. The most common cause of hypothyroidism is an autoimmune disorder known as Hashimoto's thyroiditis. Autoimmune disorders occur when your immune system produces antibodies that attack your own tissues. Sometimes this process involves your thyroid gland.

  Scientists aren't sure why this happens, but it's likely a combination of factors, such as your genes and an environmental trigger. However it happens, these antibodies affect the thyroid's ability to produce hormones.