What is heavy or abnormal menstrual bleeding?
Menstrual periods are considered heavy or abnormal if a young woman has periods that last longer than eight days in a row. It also includes bleeding that occurs more often than every three weeks and requires changing a pad or tampon every hour or less than an hour during menstruation. Heavy menstrual bleeding may also cause fatigue, dizziness or other signs of anemia.
What causes heavy or abnormal menstrual bleeding?
In girls and young women, heavy or abnormal menstrual bleeding most often occurs because of an imbalance of hormones. The body produces a female hormone called estrogen at the beginning of puberty. Estrogen causes the lining of the uterus to grow thicker. The body also makes a hormone called progesterone after ovulation. Progesterone causes the lining of the uterus to mature and thin over time.
For many girls and young women, ovulation does not occur regularly in the first several years after getting their first period. Without monthly ovulation, the lining of the uterus grows thicker due to the presence of estrogen without the balance of progesterone. This causes irregular, frequent, heavy and prolonged periods.
Another much less common cause of heavy bleeding is a bleeding disorder, which means the blood is not clotting as it should. Structural problems like fibroids, polyps or other growths are rarely the cause of bleeding in girls and young women.
Who gets heavy or abnormal menstrual bleeding?
Heavy menstrual bleeding due to hormonal factors is more common in the first few years after getting a menstrual period. This is because it often takes several years for girls to have regular and monthly ovulatory cycles.
Heavy menstrual bleeding due to a bleeding disorder is often due to an inherited or genetic condition. Let your doctor know if there is a family history of heavy bleeding in any close relative like siblings, mother or father.
We also recommend these free smartphone apps for tracking menstrual bleeding:
- Search “Sisterhood” in the app store. You can find information at the Sisterhood website.
- Search “Clue” in the app store. You can find information at the Clue website.