Frequent urination in women can be caused by pregnancy, or by diseases such as urethritis and hyperthyroidism. 1. Pregnancy: When a woman is pregnant, the enlarged uterus will, to a certain extent, cause pressure on the bladder, and then will reduce the bladder capacity, so there will be frequent urination, which is a normal physiological phenomenon. 2. Urethritis: This disease is associated with gonococcus, Chlamydia trachomatis, mycoplasma, Trichomonas vaginalis and other pathogenic microbial infections, and can be transmitted through sexual contact. Because the female urethra is short, narrow and close to the anus, it is easy to be infected. Patients will experience symptoms such as frequent urination, itching in the urethra and painful urination. 3. Hyperthyroidism: This disease is mainly caused by overactive thyroid function, which makes the thyroid hormone secretion too much, and may be related to eating a lot of high iodine food, thyroid nodules and other reasons. Because hyperthyroidism will make the body’s metabolism hyperactive and increase the system excitability, so some patients will have frequent urination, excessive sweating, diarrhea and other symptoms. In addition, frequent urination in girls may also be caused by ovarian cysts, neurogenic urinary frequency, cystitis and other diseases. If girls urinate frequently to exclude physiological phenomenon, need to go to the hospital in time, clear specific causes, under the guidance of the doctor treatment.