Up to 14% of women experience abnormal uterine bleeding, such as heavy periods, long or short periods, or bleeding between periods. Learn about some of the biological and environmental factors that can influence your menstrual cycle and contribute to abnormal bleeding.*

The menstrual cycle

Every month, your body prepares for pregnancy. Among other things, changes in hormone levels tell the lining of your uterus to become thicker. If pregnancy does not occur, this excess lining is shed from the uterus and you get your period.

The first day of your period is considered day one of your menstrual cycle, a month-long series of changes in your body that allow for a possible pregnancy. 

The average menstrual cycle lasts 28 days, although a range of 21 to 35 days is considered normal, and typically results in less than four tablespoons of blood loss. 

When is uterine bleeding considered abnormal?

Every woman experiences their menstrual cycle differently, but it’s estimated that 9-14% of women experience some form of abnormal uterine bleeding. This can include:

• Spotting between periods
• Bleeding after sex
• Heavy menstrual bleeding, such as needing to change a pad or tampon every hour
• Having a period that lasts longer than seven days
• Bleeding after menopause
• Having a menstrual cycle out of the 21-35 day range

While these are all considered abnormal, every woman’s body is unique and responds to monthly hormone fluctuations differently. If you’re experiencing abnormal bleeding, speak with your OB-GYN to get a better understanding of your specific situation.

What causes abnormal bleeding?

There are many possible causes of abnormal uterine bleeding.

Your estrogen levels increase in the days just prior to the release of an egg from your ovary. Afterward, estrogen falls and progesterone rises. This hormonal shift can cause spotting. Though it’s considered abnormal bleeding, many women experience it, and there are usually no additional symptoms. Ovulation bleeding typically only lasts for a few days, and those who experience it tend to have it on a consistent basis.

Stress can also cause changes to your menstrual cycle. When you’re stressed, your hormone levels are affected, particularly the amount of cortisol in your body. Cortisol suppresses reproductive hormones and, in turn, ovulation, telling the body that it’s not ready to support a pregnancy. This stress response can cause menstrual regularity, and even missed periods.

Other possible causes of abnormal bleeding can include:

• Uterine fibroids, or noncancerous tumors that develop in or on the uterus
• Certain medications, such as aspirin, copper IUD, birth control, and blood thinners
• Pelvic inflammatory disease (PID), a bacterial infection in the reproductive organs
• Adenomyosis, when tissues that line the uterus grow into the muscular uterine wall

If you’re experiencing abnormal uterine bleeding, consider keeping a menstrual cycle journal. Tracking your bleeding can be helpful when speaking with your healthcare provider. 

*Thacker, D. (2022, December 13). Ovulation Bleeding: What Causes It? Healthnews. https://healthnews.com/family-health/reproductive-health/ovulation-bleeding-what-causes-it/