Generally there is no problem with long duration of menstruation at the beginning, but it is abnormal when it lasts for a long time and the amount of menstruation is too heavy.
When a girl enters puberty, her genitals, endocrine system and body will gradually develop and mature due to the increase in the levels of gonadotropins and ovarian sex hormones in her body.
Generally, girls will have their first menstruation at the age of 13 to 14, but at this time, the hormone regulation function of the body is immature, making the menstrual cycle irregular, so the first menstruation lasts for a long time is generally not a problem, and can be observed for the time being. However, when the period lasts for a long time and the amount of menstruation is too heavy, it is not normal and there may be abnormal uterine bleeding.
The first menstruation is an important sign of puberty, and the menstrual cycle is usually normalized after about 5 to 7 years, when the ovaries establish a regular cycle of ovulation. The age of menarche may also be as early as 11 or as late as 16. It is important to pay attention when menstruation does not occur beyond the age of 16, and hospitalization is required to identify the cause and to follow medical advice in a timely manner.