Abnormal Menstrual Bleeding – What Could Be the Causes?

Abnormal menstrual bleeding can mean different things to different women, in terms of the amount of bleeding per period, the length of a monthly cycle, the number of days of bleeding, amount of cramping or pain experienced, type of discharge and various other factors. It is important for each woman to know what is normal for her, so that she can quickly detect when things are not normal.

While for one woman it may be perfectly normal to have a 35 day cycle with 4 days of bleeding, for another woman it may be as normal to have a 25 day cycle with 6 days of bleeding (though the ‘average’ is supposed to be a 28 day cycle with 5 days of bleeding). Similarly one woman may bleed comparatively heavily and have a longer period whereas another may have only light spotting and have only 3 days of bleeding.

So ‘abnormal’ here means abnormal for a given woman; or a change (increase, decrease, frequency, etc.) of any sort in a woman’s monthly cycle or things like mid-cycle bleeding.


Abnormal menstrual bleeding could be due to various causes. Here are some of the major ones.

1. Hormonal Imbalance

This could be experienced at the beginning of a female’s reproductive life (puberty) or at the end (menopause). The fluctuations in hormonal levels experienced at these junctures of life are normal and in a majority of cases will settle and normalize in time and without significant intervention. However, other hormonal imbalances should always be checked out and treatment, if any required should be started.

2. Birth Control

Any hormonal form of birth control will cause some changes in a woman cycle in terms of amount or frequency of bleeding. While some intrauterine devices increase bleeding somewhat, others reduce it and may even eliminate it. The oral pill also tends to reduce bleeding slightly and menstrual cramps very considerably.

3. Pregnancy

Implantation bleeding is normal in many women and occurs about 10 days after conception. However if the bleeding is caused by a miscarriage or by an ectopic pregnancy, this needs emergency medical attention.

4. Gynecological Conditions

There are various conditions that may cause abnormal bleeding – polyps, fibroids, endometriosis, benign (non-malignant) or malignant (cancerous) tumors, certain infections such as pelvic inflammatory disease or lupus, and so on.

It is best to have any abnormal menstrual bleeding investigated to try finding the underlying cause. Whereas some may be perfectly innocuous, other conditions could be life threatening.