图示:子宫腔打开后的子宫内膜过度增生
这是由于雌激素升高引起的，这种增生表现为细胞数目的增多，结果可以使组织体积增大，但细胞结构正常。并非所有的过度增生都是正常的，有时候可以是非典型增生，非典型增生有时可以恶化，称其为癌前病变。
The large fronds of endometrium seen in this uterus opened to reveal the endometrial cavity are a result of hyperplasia. This resulted from increased estrogen. With hyperplasia, there is an increase in cell numbers to produce an increase in tissue size. However, the cells are normal in appearance. Sometimes hyperplasias can be "atypical" and the cells not completely normal. Such conditions can be premalignant.