When a woman is 15 years old, she is still in an unstable stage if she has just started her period, and in a stable stage if she has been menstruating for 2 years or more. Women usually have their periods at the age of 11 to 16. When menstruation has just started, the gonadal axis in the body has not yet been fully established, and there is no regular ovulation, so hormone secretion is in an unstable state at this time, and menstruation may also be irregular. If menstruation has just started at the age of 15, then it may be in an unstable state. If menstruation has been occurring for 2 years or more, then the gonadal axis has been fully developed and regular menstruation will occur. If menstruation is abnormal in a 15-year-old woman, it is recommended that she seek medical attention in time and receive standardized treatment under the guidance of her doctor to promote improvement of her symptoms.