The main reasons for the shortening of the period from 6 days to 4 days are the following: 1. It may be a normal reaction due to ageing, as women’s ovarian function will gradually weaken with age, and the hormone level in the body will slowly decrease, thus leading to a shortened menstrual cycle and a reduction in endometrial shedding, resulting in a shorter menstrual period. 2. The company’s main business is to provide a wide range of products and services to the market. It is advisable to use medication to regulate the treatment after these conditions appear.