The average age of puberty has decreased over the past few decades. As a result, girls are starting their menstrual cycles earlier and earlier. This is in part because of genetics, environment and diet.

The menstrual cycle, and puberty in general, starts as a result of a complex network of communication between the brain and the reproductive organs. For the first few years the menstrual cycle can vary and be quite irregular. It is as if the brain and the reproductive organs are not speaking the same language to start, therefore, the menstrual cycle takes a while to normalize.

For adolescents, the menstrual cycle (from the first day of one period to the first day of the next period) can be 21-45 days. The actual number of days of bleeding varies from 2-7 days. There are roughly 10% of young women who have periods that are longer than 7 days.

For the first 1-3 years after the menstrual cycle begins, the ovaries do not ovulate regularly. This causes not only a build of tissue in the uterus but irregular signals to the brain, resulting in heavy and unpredictable periods.

If a young woman complains of “vaginal bleeding” it is important to first determine if the bleeding is actually coming from the uterus. If the bleeding usually occurs after intercourse then the bleeding may be from the cervix and not the uterus. If the bleeding is during/after urination or a bowel movement, this may indicate the issue is at the level of the bladder or intestines/rectum.

The most common cause of irregular periods during adolescence is the miscommunication between the brain and the reproductive organs. However, this may be the first time a bleeding disorder becomes obvious. Irregular periods may also indicate an abnormally functioning thyroid gland or an infection. If a young woman is excessively underweight or overweight there may be changes in her period, as well.

The cause of the irregular bleeding is what determines the treatment options.

If a patient presents with anemia (low hemoglobin) after prolonged bleeding then a blood transfusion may be necessary as part of a thorough evaluation.

In general, a pregnancy tests is always checked to make sure that the bleeding is not because of a pregnancy complication. A thorough menstrual history will be obtained including a sexual history. Family and social histories should be reviewed to determine if there are genetic bleeding disorders or activities that can contribute to heavy periods, respectively. A physical exam may be performed and a pelvic ultrasound and labs can be ordered.

It is important to discuss the patterns of a young woman’s menstrual cycle with her. Some young women do not seek help until they have developed significant anemia and require emergent blood transfusion. A consultation with a primary care provider or gynecologist can be a useful first step in determining the causes of abnormal bleeding and treatment options.