Irregular menses

Irregular menses

The term irregular menses or irregular periods refers to menstrual cycles that have abnormal differences in length. Women can experience various kinds of this condition. As a matter of fact, it is normal for women to have length variations of at least 4 days between the shortest and longest, and this circumstance is not thought of as involving irregular periods.

Classification by length

One way of classifying variations is, as mentioned above, by checking the difference between the longest cycle and the shortest one. If that amount is between 8 and 20 days, then in such a situation the irregular periods are moderate. Taking it a step further, quite abnormal cycles are those that differ by more than 21 days.

Another method of measuring the regularity of cycles is by simply checking how often they last. Cycles that are between 21 and 36 days are within the normal range, whereas those outside are abnormally brief or drawn out.

Classification by types

Irregular periods can come in different forms. Three possibilities are discussed on this page.


This condition is one infrequent periods. Generally, it refers to those with intervals of more than 35 days, or on a yearly basis, those that occur between 4 and 9 times over the course of a year. There are many possible reasons for oligomenorrhea, including thyroid issues such as thyrotoxicosis (clinical manifestations of hyperthyroidism) and Graves’ disease. This form of irregular periods can also occur in female athletes. Keep in mind that it should only be considered such a situation if menstruation regularly occurred in the past, and then became infrequent. Amenorrhea refers to a complete stop of menstrual cycles in a woman who is still in the reproductive age.


In this condition, bleeding also happens more often than normal, and at irregular intervals. The time in which the bleeding occurs can be lengthy, and the menstruation can be more than normal. Like metrorrhagia, this situation can also cause anemia. Irregular periods of this type can be brought on by various causes, ranging from hormonal imbalances to cancer. Menorrhagia is a variation of this condition, however, in it heavy levels of bleeding occur at regular intervals.


This medical term refers to bleeding that takes place at irregular times, especially between the times expected for menstruation. It could be related to a post-menopausal period, however, there are numerous possible medical causes for this situation. If it occurs frequently, metrorrhagia could lead to anemia due to continued loss of blood.