When women have hypomenorrhea they have menstrual periods that involve very little bleeding. This bleeding is considered below average, hence the prefix hypo, which means lower than or under. This condition may have entirely benign causes, requiring no treatment. Other times it can indicate ongoing problems that should be addressed. Figuring out the cause determines if treatment or investigation of the problem is necessary.

Some benign causes of hypomenorrhea include genetic predisposition, use of hormonal contraceptives, and previous size-reducing uterine surgery. By genetic predisposition, it’s simply meant that some women have very light periods, and this might be seen in their family history, where several generations of women have experienced similarly light flow. Provided that light periods don’t interfere with fertility and no other menstrual problems are present, this doesn’t need to be treated.

Birth control pills and other hormonal birth control methods like the patch can cause periods to become extremely light. Some hormonal birth control methods are marketed for reducing the total number of periods per year and causing light flow. Since this is a desired side effect of these pills, it’s not a cause for concern. Uterine surgery that has reduced the size of the uterus is generally thought of as a likely explanation for hypomenorrhea, and the condition might only be investigated if it were creating additional problems.

There are other causes of hypomenorrhea that are not exactly benign, but still usually don’t express a serious problem unless they are ongoing. High levels of stress may cause an occasional light period, or a succession of them. Persistently poor eating habits that include fasting or near starvation also might reduce menstrual flow. Most of the time, if these are the causes of hypomenorrhea, they are transient and might only affect one or two periods. If intense stress continues or extremely poor nutrition is present at all times, these conditions necessitate the guidance of a doctor to help manage stress, discuss troubles with eating, or to plan a more nutritional diet.

Another of the causes of hypomenorrhea that does warrant investigation and some medical help is an imbalance of different types of hormones. These can be the main “female” hormones like estrogen or progesterone, or they might be hormones like thyroid hormones, which help to regulate many of the body’s systems. Doctors can evaluate hormonal levels by taking blood tests.

Sometimes this condition makes achieving pregnancy difficult because the body doesn’t establish enough uterine lining each month to sustain a pregnancy, but this matter is a little confusing. Some women with hypomenorrhea are able to get pregnant and have children. Yet, women who are not on treatments like hormonal birth control should not assume a light period correlates to low fertility levels.

It’s important to mention conditions like hypomenorrhea at yearly gynecological exams where doctors can determine if any further investigation is warranted. If light periods are accompanied by any other unusual symptoms or if periods completely recede, waiting a full year is not advisable. Women should talk to their doctors earlier in these instances.