Is it normal for a 15 year old to not have a period?

Women's menstruation is regulated by the brain-pituitary-uterine-ovarian gonadal axis. Mental factors, mood swings, changes in the environment, pregnancy, age, illness, medication, and health conditions can all cause abnormalities in the function of this gonadal axis and lead to irregular menstruation. Let’s discuss whether it is normal not to have menstruation at the age of 15?

If a girl does not have her period at the age of 15, it is necessary to check the development of her secondary sexual characteristics. If there is breast development, external factors may also cause pubic hair, labia majora, and labia minora to grow and develop, then the absence of menstruation can be temporarily observed for one year. If she does not have her period at the age of 16, then it is abnormal and further examination is necessary.

If the secondary sexual characteristics do not grow and develop, and there is no menstruation by the age of 15, that is also abnormal. It is important to get checked as soon as possible. If the secondary sexual characteristics, that is, the breasts and private parts, have not changed, then there may be a congenital growth and development abnormality.

The first time a girl has her period is called her first menstruation. Young girls and their parents are very concerned about the timing of their first menstruation and hope that the first menstruation is normal. However, I don't quite know when the normal first menstruation should be, so I can't tell whether the time of the first menstruation is normal. According to relevant statistics in our country, most girls have their first menstruation between the ages of 12 and 16. For example, a related company conducted a survey on the menstrual conditions of 130,000 women in 29 provinces, municipalities, and autonomous regions across the country from 1978 to 1980, and found that the youngest age of menarche was 9 years old, the oldest was 21 years old, the vast majority was 12-19 years old, and the average was 15 years old. The most common age for menarche among women in big cities is 15 years old, while the most common age for women in rural areas is 16 years old. Another research material shows that the earliest age structure for first menstruation is in Guangzhou and Beijing, at 13.3 and 13.6 years old respectively; the latest is in Shandong Province, with an average of 15.4 years old.

The first menstruation comes early, mid-day or late, which is generally believed to be closely related to genetic inheritance. If the mother's first menstruation is early, the daughter's period will also be early; if the mother's first menstruation is late, the daughter's period may also be late. But this is not certain, it will continue to be affected by other factors. There is a certain correlation between the early morning, mid-day and late night of the first menstrual period and cohabitation in big cities and rural areas. From the above statistics, it can be seen that the age of first menstruation for urban girls is earlier than that for rural girls. The reason is that it is generally believed that in groups with higher living standards, better nutrition and physical condition, girls not only have faster physical development, but also have earlier menarche.