The lack of menstruation for several months at the age of 16 is generally associated with ovarian dysplasia, psychosomatic abnormalities, polycystic ovary syndrome, drug effects and pregnancy, and requires clear identification of the cause and targeted treatment. 1. Ovarian dysplasia: due to the lack of estrogen and progesterone, the endometrium is unable to grow and shed, and thus cannot come into bloom. Patients need to take estrogen in appropriate amounts under the guidance of a doctor and according to their own body’s hormone levels, such as ethinyl estradiol cyproterone tablets, etc.; 2. Psychosomatic abnormalities: a few months of menstruation at the age of 16 may be caused by factors such as stressful schoolwork, poor interpersonal relationships or poor parent-child relationships. You can alleviate the symptoms by relieving anxiety and tension and reducing mental stress. It is recommended to eat more light, nutrient-rich foods such as kiwis and oranges; 3. Polycystic ovary syndrome: In addition to scanty menstruation, if there are also symptoms such as obesity, acne, and vigorous body hair, it may be polycystic ovary syndrome. It is necessary to confirm the diagnosis through ultrasound, endocrine examination and other report results, commonly used drugs such as progesterone, clomiphene, etc. It is recommended that patients adjust their lifestyles, regular living and avoid staying up late; 4. If a woman is fertile and has sex, she needs to consider the possibility of pregnancy, which can be diagnosed through early pregnancy test or blood test for HCG and progesterone.