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8 Reasons for Missed Periods or Absence of Menstruation

Some women’s periods arrive each month like clockwork. For others, periods are unpredictable and may come as a surprise. Sometimes they don’t happen at all! But this doesn’t necessarily mean you’re pregnant.
A woman holding a calendar with red question marks on it, symbolizing an absence of menstruation

Late periods or missed periods may happen for a variety of reasons apart from pregnancy. Common causes of missed or irregular periods range from hormonal imbalances to serious medical issues. Let’s discuss the main reasons for a missed period and when you should contact a doctor. 

Is it normal to miss a period? 

There are two times in a woman’s life when it’s normal to have irregular periods: when you first start having them (puberty) and at the beginning of menopause. On average, most women usually get their periods every 28 days. But a menstrual cycle in a healthy woman can last anywhere from 21 to 35 days. Apart from puberty, menopause, and pregnancy, a missed period may be an indication of a health issue. 

Is it possible to miss a period for a month?   

Yes, you may have a missed period for a whole month for many reasons other than pregnancy. The reasons why you miss your period for a month may include stress, low body weight, obesity, polycystic ovary syndrome (PCOS), use of birth control, certain chronic diseases, early perimenopause, and thyroid issues. 

No period for three months: is it okay?

Not having your period for three months or more is known as secondary amenorrhea. This can happen for a variety of reasons. Natural causes of an absence of menstruation for three months include menopause, pregnancy, and breastfeeding. Certain lifestyle factors including stress and excessive exercise may also cause it. Furthermore, having excessive body fat or low body fat may also cause a missed period. Tumors on the pituitary gland or hypo-/hyperactivity of the thyroid gland can also cause hormonal disbalances and trigger secondary amenorrhea. Low levels of estrogen or high levels of testosterone can also cause a missed period. 

Genetic disorders such as Swyer syndrome and Turner syndrome result in a lack of menstruation without proper hormone replacement therapy. Some women experience a missed period because of medications such as antidepressants, antipsychotics, chemotherapy drugs, and medicines to treat hypertension. You could also have no period for three months or more if you have just stopped taking birth control pills. 

Physical defects including problems in your reproductive organs could also cause delayed or missed periods. 

How much delay in periods is normal?

You can calculate the length of your menstrual cycle by counting from the first day of one period to the first day of the next. Typical menstrual cycles range from 21 to 35 days. If you are getting your periods within this range, then they are normal.

A woman with a missed period holding a clock waiting for her period to arrive

Causes of missed periods other than pregnancy 

Some of the causes of missed periods, besides pregnancy, are as follows:

  • Stress: it is one of the most common reasons for a missed period. Stress can result in a hormonal imbalance and even affect the hypothalamus — the part of the brain that helps regulate your periods. Stress can also lead to sudden weight loss or gain or other illnesses, all of which can affect your cycle. Stress can arise from a lot of factors such as traveling, professional and relationship issues, emotional problems, financial issues, etc. 
  • Low body weight: low body weight is also a potential reason for a missed period. Women with eating disorders including bulimia or anorexia nervosa may experience an absence of menstruation. If your body weight is below 10 percent the normal range for your height, then you might stop ovulating because of hormonal changes. Athletes who participate in the extreme forms of exercise like marathons may also experience missed periods. 
  • Obesity: similarly to low body weight, obesity can also result in hormonal changes leading to an absence of menstruation. 
  • Polycystic ovary syndrome (PCOS): PCOS is a condition in which your body produces more of the male hormone androgen than normal. Due to this hormonal imbalance, cysts form in the ovaries, making ovulation irregular or stopping it altogether. This results in a missed period. Together with androgens, other hormones such as insulin can also get thrown out of balance with PCOS. 
  • Birth control: going off or starting birth control can produce changes in your menstrual cycle. Birth control contains the hormones progesterone and estrogen, which prevent your ovaries from releasing eggs. It might take up to six months for your period to become regular again after you stop or start taking birth control pills. Other kinds of hormonal contraceptives that are injected or implanted can also cause missed periods. 
  • Chronic diseases: certain chronic illnesses such as celiac disease and diabetes can also affect your period. Blood sugar changes can cause hormonal changes, and poorly controlled diabetes can cause irregular periods. Celiac disease causes inflammation in your small intestine and prevents your body from absorbing vital nutrients. This can also cause missed or late periods. 
  • Thyroid issues: an under- or overactive thyroid gland can also cause irregular periods. The thyroid gland regulates the metabolism of your body, so thyroid issues can also affect hormone levels. This can cause you to miss a period. 
  • Early perimenopause: in most women, menopause begins between the ages of 45 and 55. If symptoms of menopause start before the age of 40, it’s considered early perimenopause (the transitional stage that precedes menopause). Early perimenopause means that the supply of your eggs is declining. This can result in a missed period and eventually the end of menstruation. 

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Is a missed period ever cause to ask for a doctor’s help? 

It might be a good idea to talk to your doctor about a missed period or irregular periods, especially if your periods are usually regular. Your doctor can help you get to the bottom of your missed period and suggest appropriate treatment options. 

Visit your doctor if you suffer from the following symptoms:

  • You’ve missed your period three or more times in a year
  • You get a period more frequently than every 21 days
  • You get a period less frequently than every 35 days
  • Bleeding lasts for more than seven days
  • Bleeding is heavier than normal
  • You have severe pain during your period
  • You have a fever
  • You have postmenopausal bleeding (bleeding after you have entered menopause and not had a period for one year)

A missed or late period can occur for multiple reasons apart from pregnancy. Potential causes range from hormonal imbalances to serious medical issues. Irregular periods normally occur during puberty, at the beginning of menopause (early perimenopause), and during pregnancy.

Apart from that, a missed period can sometimes indicate a health issue. Some causes of a missed period other than pregnancy include stress, low body weight, obesity, polycystic ovary syndrome, use of birth control, chronic diseases, thyroid issues, and early perimenopause.

If you’re experiencing a change in the pattern of your normally regular periods, make sure to bring it up with your doctor. 

https://www.healthline.com/health/womens-health/why-is-my-period-late

https://www.webmd.com/women/why-is-my-period-so-random#1

https://www.healthline.com/health/menstruation-absent#causes

https://www.medicalnewstoday.com/articles/322893.php

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    I've tried several period tracker apps on the market and nothing is as good as Flo. It's accurate, detailed providing you with an abundance of parameters to log, and they even provide useful articles and surveys to help you better understand the complex nature of the female body.

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