When a girl enters puberty, a mature egg is discharged from her ovary every month. If the egg is not fertilized, the endometrium will naturally fall off, causing uterine bleeding (stomach pain and back pain when the endometrium falls off), which is menstruation. The first menstruation is called menarche. The age of menarche is generally 1 1~ 17. The menstrual cycle is the same as the ovarian ovulation cycle, about 28~30 days.
Generally speaking, girls' breasts grow before 1 1 year, pubic hair begins to grow at 12 year, and the growth peak is before 12 year. 12 middle age is the period of body shape change, 13 early axillary hair growth, 13 middle age is menarche.
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⑴ Mental symptoms are the main symptoms: common nervousness, irritability, general fatigue and weakness, sometimes causing headache, insomnia and inattention.
⑵ Physical symptoms are the main symptoms: common hand, foot and face edema, abdominal flatulence, abdominal distension in some people, constipation, abdominal pain and breast pain in most girls.
The morning and evening of menarche is also related to climate. Generally, when the temperature is high in tropical areas, the age of menarche is early for girls, and it is late for girls in cold areas, which may be related to the pineal gland in the human brain. The pineal gland secretes a hormone called melatonin. In recent years, it has been found that the secretion of melatonin is related to light. It secretes more in the dark and has a strong inhibitory effect on gonads; Under light, the secretion is less, and the inhibition on gonad is weak. This makes the phenomenon of precocity in tropical areas scientifically explained.
In addition, the morning and evening of menarche is also related to physical health, mood and nutrition. In short, the morning and evening of menarche are influenced by many factors, so individual differences may be great. As early as 9 years old and as late as 18- 19, if there are no other abnormal conditions, it is regarded as the normal range. If you come to menstruation at the age of seven or eight, or don't come to menstruation at the age of 22, and there are other symptoms, you should go to the hospital to find out the reason and treat it as soon as possible. Adolescent menarche is only a sign that the reproductive system begins to work, and the function of the reproductive system is not yet mature, so during menarche, the menstrual cycle is often irregular. According to the survey, from menarche to the second menstrual period, most people are more than half a year, and some are eight or nine months. Menstrual period turns to normal menstrual cycle, usually within two years. We should have a full understanding of this irregular menstrual cycle, and don't take medicine indiscriminately because of illness, so as not to affect our health.