A girl’s body undergoes a lot of changes during puberty, and the onset of menstruation is one of the more important changes. Within a few years of the onset of menstruation, irregular menstruation usually occurs. 17-year-old low menstrual flow is commonly caused by immature physiological development, learning pressure, disease, surgery, etc. 1, immature physiological development: at the age of 17, the gonadal axis of the girl is not fully mature, the menstruation may be irregular, and some women show excessive menstruation, while some girls will show a decrease in the amount of menstruation, irregular; 2, learning pressure: most of the 17-year-old are in high school, learning pressure, will affect the lower part of the mound, and the menstrual flow is irregular. The girl’s menstrual period may be irregular. 2, study pressure: most of the 17-year-old age is in high school, study pressure, will affect the hypothalamus function, resulting in a decrease in the amount of menstruation. At this time, we should pay attention to rest, relax and avoid excessive pressure; 3, the impact of disease: some girls have pituitary disease, such as pituitary tumor, or ovaries on the growth of special types of tumors, such as follicular membranous cell tumors, granulosa cell tumors and so on, which will cause a decrease in menstrual flow. There is also a percentage of obese and hairy women who may have polycystic ovary syndrome causing decreased menstrual flow. In addition, anemia can also cause a decrease in menstrual flow; 4, the impact of surgery: have had abortion surgery or other gynecological surgery, can also cause a decrease in menstrual flow; 5, other: if the patient is too thin, or have stayed up too late, cold, etc., can also occur at the age of 17 years old menstruation is low. If you have a low menstrual flow at the age of 17, you should immediately go to the gynecology department of the hospital to look for the cause through the ultrasound of the uterine adnexa, female endocrine hormone testing and other related examinations, and then treat accordingly.