Some causes of early menstruation can include precocious puberty and irregular activity in hormone-producing glands. An early onset of menstruation is not necessarily harmful, as people can start their periods between roughly eight and 14 years of age and there are some natural outliers. A doctor may want to evaluate a patient to check for any risk factors of concern just to make sure she is healthy.
In precocious puberty, people start producing hormones associated with puberty earlier than usual. They will develop signs of puberty like changes in fat distribution and more body hair. In girls, this will lead to early menstruation. Sometimes this happens naturally, often in response to dietary factors; the better nutrition young girls get, the earlier the onset of puberty tends to be, as their bodies develop more quickly. Worldwide, the average age of puberty dropped considerably during the 20th century in response to better nutrition for growing children.
Sometimes, precocious puberty is the result of hypothyroid disease, brain tumors, genetic conditions, or damage to the adrenal gland. In these cases it is a sign of an underlying medical issue, rather than being a benign life event. A doctor can request medical imaging studies as well as blood tests to check on hormone levels to look for the cause of early menstruation. The doctor may find nothing and determine that the patient has nothing to worry about.
Glands in the body like the adrenal gland can start overproducing hormones in response to stress, dietary factors, and other issues. This can sometimes lead to early menstruation when the imbalance is prolonged. Once the body starts to go into puberty, it sets off a snowball effect. Even if the cause of the hormone imbalance resolves, the patient's body will still move into adulthood. A doctor may review the patient's medical history to determine if this is a possible explanation for experiencing puberty earlier than expected.
People who experience early menstruation may experience some social problems. Classmates sometimes make them targets of curiosity or teasing, and they may feel reluctant about engaging in sports and other physical activities. It can help to make counseling available for those who want it and to make sure that girls have the supplies they need to manage their periods, with the goal of preventing accidents. Usually a school nurse will have sanitary napkins and other supplies and can instruct students in their use if they are not familiar with the procedure.