Irregular Periods

by Eileen Bailey Health Writer

We often hear the words "irregular periods" and assume that, if the term refers to our cycle, that there is something wrong or that we are the only person who doesn't follow the regular, 28 day cycle. In fact, irregular periods are pretty common. About one in every three women will have irregular periods at some point during their reproductive years. So what does that mean?

What is a Regular Period?

Medical professionals use a 28 day cycle to signify a "regular" period. The first day of your period is considered to be Day 1 of your cycle. Somewhere around the 14th day, you will ovulate, which means your egg drops from the ovary, ready to be fertilized. If this doesn't happen, two weeks later, your uterus will shed the egg and the thickened lining of the uterus, or menstruation will occur and last from 4 to 7 days. Your body continues to go through this cycle, each month preparing for you to get pregnant and, if you do not, starting the cycle over again.

What is an Irregular Period?

But not every woman follows the typical 28 day schedule. Some may menstruate every 20 days, some every 35 days. And some woman may not follow any particular pattern, getting their period after 3 weeks one month and after 6 weeks the next cycle. Some may have their period for 2 or 3 days, others for a week. Each person's body is different and what is regular for you, may not be regular for your friends.

Your period may also fluctuate from month to month, with heavy bleeding one month and not much the following month. This is usually caused by changing hormone levels in your body and is quite common in girls during the first few years of getting their period.

Other ways your period can be irregular are:

  • Missing a period

  • Having your period for more than one week

  • Bleeding in between periods

  • Heavy bleeding (menorrhagia) or very little bleeding

  • Getting two periods in one month

What Causes Irregular Periods?

Most times, irregular periods are causes by the levels of hormones fluctuating and can be more common in young girls during the first few years of beginning menstruation. There are times, however, that other factors can contribute to irregular periods:

  • Changing birth control methods. If you have recently changed your birth control method, you may need to wait several months to see if your period settles back into a regular cycle

  • Stress. Stress impacts hormones, which, in turn, can impact your menstrual cycle. If you are worried, anxious or overly tired, this can have an effect on your period.

  • Diet. Not taking in enough calories can cause you to miss a period. Overeating can have the same effect.

  • Exercise. While regular exercise is good for you, intense exercise can cause you to miss a period.

  • Medications. Certain medications may cause you to have irregular periods, if you are taking medications, talk with your doctor about the possible impact on your menstrual cycle so you are prepared.

  • Hormone imbalance. Some thyroid disorders can cause irregularities in your menstrual cycle.

In some cases, irregular periods can be caused by other, more serious medical conditions. If you have heavy bleeding, excessive cramping, nausea, fainting or have gone for more than one year without having a period, you should speak with your doctor. A few of the possible conditions which can cause irregular periods include polycystic ovary syndrome, endometriosis, pregnancy, cancer or inflammatory bowel disease.


Most times, no treatment is necessary, however, if you are experiencing problems, such as heavy bleeding, that is interfering with your daily life, your doctor can talk with you about possible medical treatment, such as hormonal contraceptives which contain estrogen and progesterone and can help regulate your period.

Other treatments would include those to address the underlying cause, such as stress relief techniques or eating a balanced diet. In most cases, once the underlying cause is treated, your cycle will regulate itself.


"Irregular Periods," Date Unknown, Staff Writer, University of California Student Health Services

"Irregular Periods (Oligomenorrhea)," Date Unknown, Staff Writer, Epigee Women's Health

"What Are Irregular Periods?" 2010, Feb 9, Christian Nordqvist, Medical News Today

Eileen Bailey
Meet Our Writer
Eileen Bailey

Eileen Bailey is an award-winning author of six books on health and parenting topics and freelance writer specializing in health topics including ADHD, Anxiety, Sexual Health, Skin Care, Psoriasis and Skin Cancer. Her wish is to provide readers with relevant and practical information on health conditions to help them make informed decisions regarding their health care.