Common Causes Of Irregular Menstrual Cycles

For many women, their menstrual cycle is extremely regular, and these women can expect to start their period on exactly the same day each month. However, there are also several women who deal with irregular periods that start on different days or they might skip a period for one or several months altogether. Here are a few of the most common reasons why a woman will have an irregular menstrual cycle.


Otherwise known as menopause transition, perimenopause occurs when a woman's estrogen levels begin to fall. Depending on the woman, this transition into menopause can last for several months or several years and occurs anywhere from a woman's mid-thirties to their mid-fifties. In addition to irregular periods, including periods that are shorter than normal, women in perimenopause can also experience the following symptoms:

  • Increased urination
  • Hot flashes
  • Night sweats
  • Mood changes, such as depression or irritability
  • Insomnia

When a woman does not have a menstrual cycle for 12 consecutive months, she will transition from perimenopause into menopause.


The lining of a woman's uterus is covered with a special tissue called endometrial tissue. When this tissue begins to grow outside the woman's uterus, such as the intestines, ovaries, fallopian tubes, or other areas of the pelvis, it causes a condition called endometriosis.

In addition to irregular or missed periods, a woman with endometriosis will also experience painful periods, pain during sex, chronic back pain, and infertility. In addition to managing the pain associated with endometriosis, your gynecologist will recommend a treatment for this common condition. For example, if you are not trying to get pregnant, birth control pills or an intrauterine device, IUD, can regulate the menstrual cycle and lessen the symptoms of endometriosis.

Stress, Poor Diet, or Extreme Weight Loss

There are several everyday lifestyle issues that can trigger irregular periods. One of the most common is stress, which can interfere with the portion of the brain that regulates a woman's hormonal balance. A poor diet, losing too much weight or being underweight, and exercising too much can also cause an irregular period.

When To See Your Gynecologist

If you experience an irregular period for several months, especially if you are under the age of 45, contact your gynecologist. This includes if your period does not occur for several months, if your cycle lasts for longer than seven days, or if your menstrual cycle occurs more often than every 21 days or longer than every 35 days.

Whether you are diagnosed with endometriosis or need to make some lifestyle changes, there are several reasons why you might have an irregular period. Contact your gynecologist with any more questions.