What is abnormal uterine bleeding?

Abnormal uterine bleeding is when you bleed between your monthly periods, or when you bleed for too long or it is an extremely heavy flow. Normal menstrual flow typically lasts approximately five days and occurs every 21 to 35 days.

How common is abnormal uterine bleeding?

Abnormal uterine bleeding is not always reported by women experiencing symptoms. Because of this, 3% to 35% of women worldwide may have abnormal uterine bleeding. It is estimated that about 1% of women in the U.S. are impacted by abnormal uterine bleeding.

What are the causes of abnormal uterine bleeding?

There are many causes of abnormal bleeding, including:

  • Structural abnormalities in the uterus, including:
    • Fibroids (non-cancerous growths of muscle in the uterus)
    • Polyps (non-cancerous growths on the lining of the uterus and cervix)
  • Uterine cancer
  • Cervical cancer
  • Blood thinners for anticoagulation (medications that reduce the risk of blood clots)
  • Platelet dysfunction
  • Early pregnancy
  • Hormonal changes

Polycystic ovary syndrome (PCOS) is a condition where cysts grow in the ovaries. PCOS may lead to hormonal imbalance. This condition may cause your periods to come at different times or not at all. PCOS is caused when certain hormones are out of balance. When this happens, you may have difficulty getting pregnant. You may grow hair on your body and face. Also, the hair on your scalp may get thinner.

Women who are going into menopause or are in menopause are more apt to have changes in hormones. The changes can cause the lining of the uterus (endometrium) to get thick. This can cause bleeding, or abnormal menstrual cycles in terms of long the cycle lasts and how heavy it is (duration and quantity). For women who are in menopause, any bleeding should be thought of as not normal and should be investigated.

What are the signs and symptoms of abnormal uterine bleeding?

The signs of abnormal uterine bleeding can vary. Some signs that your bleeding may be abnormal include:

  • Menorrhagia (heavy menstrual bleeding)
  • Bleeding at unusual times (between periods, after sex, during menopause)
  • Unusually long periods (seven days or longer)
  • Inconsistent menstrual cycles

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