Periods are supposed to be on a timely schedule, right? Not exactly. They come just about once a month for many, but there are several cases in which this isn’t true. Even for two women who are considered to have regular periods, their time between periods can vary by as many as 14 days. So, when is a period considered irregular?

According to, a period is irregular if one of these two conditions apply:

  • Your menstrual cycle is shorter or longer than average, meaning the time between the end of one period and the beginning of the next is less than 24 days or more than 38 days.
  • Your cycle length varies by more than 20 days from month to month.

This is less of a concern for teenage girls or perimenopausal women, those entering menopause, because irregular periods are to be expected as you transition in or out of an active menstrual cycle. If you are comfortably in between puberty and menopause and are experiencing an irregular period as described above, you may want to consider consulting with your doctor.

Why is My Period Irregular?

There are a range of possible contributors to periods that don’t arrive as planned, some less concerning than others. These factors include:

  • Eating disorders, such as bulimia and binge eating
  • Thyroid problems
  • High amounts of the hormone prolactin in the blood
  • Medications for epilepsy or anxiety
  • Polycystic Ovary Syndrome (PCOS)
  • Primary Ovarian Insufficiency (POI), a condition that prevents ovaries from working normally before age 40
  • Pelvic Inflammatory Disease (PID), which can be caused by an STI
  • Stress
  • Uncontrolled Diabetes
  • Obesity

If you are aware that you are affected by any of these conditions, your doctor can help you map out your next steps to successfully managing your menstrual cycle. One possible solution includes hormonal birth control, like pills, shots or IUDS, and exercise and diet changes can be used in the case of eating disorders, diabetes or obesity.

Our doctors are available to answer any of your questions, whether you are experiencing an irregular cycle or are simply curious about the causes. Feel free to call and set up an appointment today at Mt. Auburn OBGYN in Cincinnati.