As a female hormone target organ, the mammary gland undergoes cyclical changes as hormone levels rise and fall in response to changes in the menstrual cycle. During this process, the most obvious change is mammary hyperplasia. Breast nodules themselves are not more related to the menstrual cycle. Breast nodules themselves are not more related to the menstrual cycle. Breast enlargement disease is evident in some people during the premenstrual period, as the glands are enlarged and there is a swelling or stabbing pain, which disappears as the menstrual period ends, called cyclical pain, which is related to menstruation. Most breast nodules are actually tumorigenic or inflammatory in nature, and have little to do with hormonal effects, so they usually change less with hormonal changes. However, after the degeneration of hyperplasia, the edema and swelling of the gland will subside, and the pain will be significantly relieved by ultrasound and mammography. After the gland has receded, the boundary of this nodule will be more clearly defined, so the examination will be more accurate. However, regardless of whether the nodule is inflammatory or tumor nodule, it has less influence with menstruation and hormones before and after.