Missed or Irregular Periods? 12 Causes Besides Pregnancy

Missed (amenorrhea) or irregular period is a common cause of worry for many girls and women. Pregnancy is the first thought that strikes girls whenever they miss a period or have irregular periods. However, this might not always be true.

There are several other factors other than pregnancy which can be the cause of missed or irregular periods.

Below is an exhaustive list of 12 reasons for missed or irregular periods. But before that let us quickly understand what does missed or irregular periods mean.

Women have about 11 – 13 menstrual periods each year; this may however vary from individual to individual

  1. Missed periods also medically termed as amenorrhea, is a condition characterized by absence of one or more than one period.
  2. When women get their menstrual cycle before 21 days or after 36 days then it is considered to be irregular periods. Alternatively, if they miss out on one cycle each month it is then considered as missed periods
  3. The basic phenomenon behind amenorrhea is when egg is not produced in the ovaries.

To further understand this, let us tread into bit detail about amenorrhea.

Amenorrhea is of 2 types: Primary and Secondary

  • Primary amenorrhea: This basically strikes girls aged 16 years and above who did not have a single period yet.
  • Secondary amenorrhea: This is the most common form of amenorrhea, wherein the women who had regular menstrual suddenly stop having their periods. [4]

1. Stress

Research has proved beyond doubt a strong relationship between stress and missed periods. You should understand that menstrual cycle is not just the function of ovaries to ovulate each month; it is a process which is controlled by your hypothalamus in the brain.

Stressful situations can alter the functioning of the hypothalamus that can cause missed or irregular periods. [5]

2. Excessive or vigorous exercising

American Academy of Family Physicians have documented that that excessive or vigorous exercising can be a strong factor for missed or irregular period [6].

This is because, excessive exercise causes deficiency of progesterone that in turn leads to a condition known as hypothalamic anovulation.

In addition to this, a high amount of energy is consumed when you exercise vigorously which then causes altered or missed periods.

3. Eating pattern and its related disorders

A diet that is low in calories and fat can also cause missed or irregular periods. This is because, your body requires 2000 calories a day and you need to have at least 16% body fat for having normal menstrual cycle.

Women who take in fewer calories and exercise more can have altered or missed periods. Eating disorders such as anorexia and bulimia can disturb your regular monthly cycle.

Being too thin or too fat (obese individuals) may also create problems during the menstrual cycle. This is so because, being obese interferes with the normal hormonal function which in turn results into missed or irregular periods.

Having low body fat signifies that there are not enough fat cells for production of estrogen which causes missed periods [7,8].

4. Drug abuse

There are certain drugs that can have a strong impact on your menstrual cycle. Medications taken for treating cancer and depression can alter your menstruation. Illegal use of drugs also has a strong effect on menstrual cycle.

5. Hormonal issues

Hormonal imbalance can cause alterations in the levels of hormones that aid in the process of ovulation.

6. Uterine scarring

If you have undergone uterine scarring due to certain medical procedures such as D&C, cesarean section during childbirth or as a treatment procedure for uterine fibroids, then very little shedding of uterine lining will take place during menstrual cycle. This will cause either very light periods or no periods at all [2].

7. Breast feeding

This is yet another common cause of missed or irregular periods. Many women do not have their regular menstruation until they have completed breast feeding. This is what happens – the hormones that aid the process of lactation may block the hormones that require for ovulation to occur; which in turn causes irregular periods [9].

8. Diseases

Diseases such as anemia, uterine fibroids, pelvic inflammatory disease, endometriosis, polycystic ovarian syndrome, diabetes, irritable bowel syndrome (IBS), liver disease and tuberculosis can also cause missed or irregular periods [1,5].

9. Contraception

Use of contraceptives have also shown to have a profound effect on menstrual cycle. The newer generation of birth control pills contains continuous hormones unlike the traditional birth control pills wherein you were required to take 21 days of pills with hormones.

The presence of continuous hormones in the new class of birth control drugs causes missed or irregular periods. The hormonal injections that are given for contraceptive purpose can also cause irregular or missed periods. Some examples of next generation drugs include Seasonale, Yaz, Yasmin and Lybrel [2].

10. Improper functioning of the thyroid gland

This is yet another potential causative factor for missed or irregular periods. Improper functioning of the thyroid gland causes hypothyroidism which in turn affects the hypothalamus in the brain.

Thyroid disease is also known for altering the production of prolactin which in turn disrupts the menstrual cycle.

11. Diet pills

Intake of diet pills can also affect the menstrual cycle. According to OB/GYN Nurse Practitioner Marcelle Pick, certain diet pills contain stimulants and caffeine and in a way triggers the body to produce more of cortisol.

Cortisol is responsible for regulation of the estrogen and progesterone; this in turn causes the periods to occur, 24 days before the due date or 35 days after the due date [10].

12. Menopause

When you experience missed or irregular periods, then you may be in the menopausal stage. If you are in your 40s then you may shows signs of menopause. Irregular and missed periods are the main signs of onset of menopause. Menopause occurs when it is almost 12 months since you had your periods [9].


How To Deal with Missed Or Irregular Periods

It is always advisable to relax and stay away from anxiety when you have missed your regular menstrual cycle. Conduct a pregnancy test at home to rule out or confirm the cause of missed periods.

If you are not pregnant then stay calm and try to avoid stressful lifestyle. A fine balance between physical and emotional well being should help in bringing back your normal monthly cycle.

You are also advised to avoid low calorie and low fat foods. If you have been vigorously exercising then it is better to restrain from it for a while.

Bringing such life style changes may restore your normal monthly periods; however if this does not happen then it is time for you to consult your doctor for further medical help.

Your doctor may perform several medical tests to confirm the cause of your missed periods. Medications and treatment regime will depend on the cause.

Remain stress free and worry free to put back your body processes in place!!


  1. http://women.webmd.com/tc/missed-or-irregular-periods-topic-overview
  2. http://www.mypregnancybaby.com/reasons-missed-period-not-pregnant/
  3. http://www.nhsdirect.nhs.uk/FemaleSexualHealthSelfCare/AbsentOrAlteredPeriods
  4. http://www.umm.edu/altmed/articles/amenorrhea-000006.htm
  5. http://answers.webmd.com/answers/2018942/can-stress-delay-your-period-and-if-so-for-how-long
  6. http://www.livestrong.com/article/403954-exercise-and-spotting-before-a-period/
  7. http://www.healthlinkbc.ca/kb/content/symptom/mispd.html
  8. http://www.livestrong.com/article/339959-weight-loss-a-late-period/
  9. http://www.mayoclinic.com/health/menstrual-cycle/MY01541/NSECTIONGROUP=2
  10. http://www.livestrong.com/article/545526-can-diet-pills-make-your-period-late/

Published on January 11th, 2018 by under Pregnancy.
Article was last reviewed on January 24th, 2018.

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