Reasons for short menstrual periods

Updated March 23, 2017

From the first cycle to the last, many women feel their menstrual cycle can be a burden. The once-a-month period puts a damper on their mood, causes water retention and can make their lives miserable. While many go through life never having a problem, a shortened menstrual cycle may be worth noting, especially when a woman generally has longer periods.

Time frame

Each woman is different in terms of how long their menstrual cycle is and how long their period lasts. For a majority of women, their average period lasts between five and seven days. Normal cycles generally fall between 21 and 45 days, although this may vary with some women depending on their lifestyles and types of medication being taken. Women generally begin their menstrual cycle by the age of 12 and continue until they reach menopause. It's not uncommon for teenagers who play a lot of sports to have delayed starts to their cycle.


For the majority of women, a shorter-than-average menstrual period is no cause for concern. As women get older, their cycles regulate and the days of bleeding may shorten. It's not uncommon for women to have periods lasting only a couple of days. Women who are worried about the decrease in the number of days on their menstrual period should consult their GP.


The menstrual cycle and period are often affected by the surroundings and lifestyle of a woman. Stress from work or relationships may cause bleeding to become more severe or stop sooner than normal. For some women, increased exercise may lead to a shorter menstruation cycle. A common reason a woman's cycle may shorten is because other women live with her. One study, conducted in 1971 by Martha McClintock at the University of Chicago, determined that women who live together often have the same cycles or very similar ones. It's common among university roommates and even female relatives to be on the same cycle. This is known as "the McClintock effect." Moving into a new situation also may cause the number of days to decrease. In serious cases of anorexia and bulimia, periods may cease completely or become very short as the woman loses weight.

Hormonal imbalance

One of the most common causes for shortness or an elongation in the menstrual period is hormonal imbalances. Women with hormonal imbalances may require oestrogen shots or medication to get their cycle back on track. Women who experience a condition known as polycystic ovarian syndrome (PCOS) might be put on medication such as glucophage to regulate their periods. Other women could be prescribed contraceptive pills to help regulate the frequency and length of their menstruation.


For most women, a shortened menstrual period is something they enjoy rather than worry about. However, for others, it could be a sign of something serious. Shortened menstrual cycles can be a cause for concern if they continue for several months. When it comes to reproductive heath, the best advice a woman can get is from her gynecologist, who has tools at their disposal to diagnose and treat serious conditions. It's recommended that all women, especially those who are sexually active, have smear tests every three years to ensure everything is working correctly and there are no signs of infection.

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About the Author

Based in Kentucky, Katy Lindamood is a full-time freelance writer. She has been writing for magazines and professional websites since 2006 and has a background in retail management and home improvement. Lindamood holds a Bachelor of Science in business administration and human resources.