The Yellow Emperor’s Classic of Internal Medicine: “The woman is seven years old, the kidney is strong, the teeth are more hair long; two seven, and the sky aoi to, any vein through, the tai-chong vein is strong, menstruation to time down, so there are children …… seven seven, any vein deficiency, the tai-chong vein decay less, the sky aoi exhausted, the earth channel is not accessible, so the form is bad and no children … …”. The menarche is the 1st menstruation of a woman, generally at the age of 13-14 years old, can be as early as 11-12 years old. The early and late menarche is mainly controlled by genetic factors, nutrition and weight also play a big role. In recent years, there is a trend towards earlier menarche. Menopause mostly occurs between 45-55 years old and is controlled by genetic and nutritional factors. Let’s briefly analyze menstruation from several aspects: 1. Period: refers to the duration of each bleeding, usually 3-7 days, mostly 3-5 days. Clinically, patients often ask: “Doctor how my menstruation drips and drips all the time, it’s been half a month.” This is a prolonged menstrual period. On the contrary, there are also patients who say how their period clears within two days of arrival, as opposed to having a shortened period. Shortened periods often occur together with decreased menstrual flow, like a difficult brother or sister. Both of these are abnormal. 2. Cycle: Many patients mistakenly take the first day of clean menstruation as the beginning of the cycle, in fact, the first day of bleeding should be taken as the beginning of the menstrual cycle, and the time between two adjacent menstrual days is called a menstrual cycle. It is usually 21-35 days, with an average of 28 days. Everyone has their own menstrual cycle and it is normal as long as the menstrual cycle is regular. For example, doctors recommend that patients have a vaginal ultrasound around the 5th day of their period to observe the endometrium. Let’s say a patient had her period on September 1 and it cleared on September 5, so when should she have an ultrasound? Yes, as I am sure many patients understand, she should come for an ultrasound around the 6th, not around the 11th. The same goes for monitoring the follicles. 3. Menstrual flow: The total blood loss during one menstrual period is the menstrual flow, which is normally 30-50ml, too much or too little is not good. Usually, if you only need to use pads during a period, you will have a low menstrual flow; if you need to change sanitary napkins frequently and the bleeding volume is particularly large, you will have a high menstrual flow. If there is a significant increase or decrease in the amount of menstruation compared to the usual situation, it is abnormal menstruation. Excessive menstrual flow is common in diseases such as gonorrhea, uterine fibroids, polyps, endocrine abnormalities, etc. Low menstrual flow can be seen in decreased ovarian function, polycystic ovary syndrome, uterine adhesions, post-abortion, etc. 4. Menstrual color: generally dark red, in addition to blood, there are endometrial debris, cervical mucus level shed vaginal epithelial cells, menstrual blood is not coagulated, and blood clots may appear when bleeding is high. Concomitant symptoms Many women experience concomitant symptoms before and after menstruation, such as emotional irritability, back pain, abdominal pain, breast swelling and pain. Even diarrhea and gastrointestinal dysfunction symptoms may occur. A few women may have headache, vomiting, menstrual regression, etc. Precautions during menstruation: 1. do not overwork, avoid strenuous exercise and physical labor; 2. do not eat cold and spicy food, avoid getting cold; 3. do not have sex, do not sit in the bath, do not wear tight pants, etc. The above is a brief introduction to menstruation, each aspect may have major or minor problems. Such as frequent menstruation, scanty menstruation, excessive menstruation, scanty menstruation, menstrual disorders, intermenstrual bleeding, dysmenorrhea, menstrual headache, breast pain, etc.