If each period comes once every 15 days, it can be diagnosed as frequent menstruation. For this condition, it is commonly caused by the following reasons: 1. endocrine disorders caused by environmental changes or emotional changes, resulting in endocrine disorders that make menstruation frequent. It is recommended to combine clinical history with laboratory tests and give appropriate treatment. 2. Frequent menstruation is caused by lesions of the endometrium, such as inflammation of the endometrium, polyps of the endometrium, cancer of the endometrium, atypical hyperplasia of the endometrium, etc., which may lead to frequent menstruation. Since submucosal fibroids of the endometrium or large fibroids between the muscle walls can also cause frequent menstruation, routine blood tests, ultrasound, sex hormone six tests, and gynecological examinations are recommended. Based on the comprehensive analysis of the results, the cause of frequent menstruation can be basically determined.