There are several reasons for thin endometrium: 1. Normal physiological phenomenon, because the degree of development of different individuals is not exactly the same, some women have thicker endometrium, naturally some women have thinner endometrium, as long as it applies to the normal physiological development of the individual can be considered normal. Unless there is an abnormality that needs to be treated, there is no need for treatment. 2. It may be caused by disease, as normal endometrium has a cyclical shedding and generation process. During this process the endometrium is renewed and plays an important role in maintaining the normal physiological and secretory functions of the endometrium. If the endothelium is thin it may be due to a deficiency of hormones that promote endothelial production, which leads to impairment of related processes such as gene transcription and translation. It may also be due to a deficiency of the nutrients involved in synthesizing the endothelium, which can also lead to thinning of the endothelium, and if this is due to these conditions treatment is required.