Unexplained Missed Periods

What Causes Missed Periods?

In order to deal properly with missed periods we need to understand and — if possible — remove the underlying causes and risk factors.  We need to ask: "What else is going on inside the body that might allow missed periods to develop?"

Diagnose your symptoms now!
  • understand what's happening to your body
  • check your overall health status
  • identify any nutritional deficiencies

Accurate diagnosis of the factors behind missed periods consists of three steps:

Step 1: List the Possible Causative Factors

Identify all disease conditions, lifestyle choices and environmental risk factors that can lead to missed periods.  Here are eight of many possibilities (more below):
  • Hemochromatosis
  • Zinc Need
  • Polycystic Ovary Syndrome
  • Anorexia/Starvation Tendency
  • Overtraining
  • Brain Tumor
  • Hirsutism
  • Hypothyroidism

Step 2: Build a Symptom Checklist

Identify all possible symptoms and risk factors of each possible cause, and check the ones that apply:
constant fatigue
fatigue after slight exertion
strictly controlled emotions
brittle hair
weak sexual desire
moderate frequency of sex
specific muscle weakness
high iodine consumption
frequent dieting
major unexplained weight gain
... and more than 120 others

Step 3: Rule Out or Confirm each Possible Cause

A differential diagnosis of your symptoms and risk factors finds the likely cause of missed periods:
Cause Probability Status
Anorexia/Starvation Tendency 94% Confirm
Brain Tumor 27% Unlikely
Zinc Need 17% Unlikely
Hirsutism 5% Ruled out
Hemochromatosis 5% Ruled out
Polycystic Ovary Syndrome 2% Ruled out
Hypothyroidism 1% Ruled out
Overtraining 1% Ruled out
* This is a simple example to illustrate the process

Arriving at a Correct Diagnosis

The Analyst™ is our online diagnosis tool that learns all about you through a straightforward process of multi-level questioning, providing diagnosis at the end.

If you indicate being premenopausal or being perimenopausal, The Analyst™ will ask further questions including this one:
Have you experienced missed periods that are unrelated to pregnancy, breast feeding, menopause or birth control pill use?
Possible responses:
→ No / don't know
→ Yes, but not in the last two years
→ I occasionally miss a period
→ I regularly miss a period or 1 to 2 in a row
→ My periods are infrequent or absent
Based on your response to this question, which may indicate either unexplained missed periods in past or unexplained missed periods, The Analyst™ will consider possibilities such as:

Amenorrhea also suggests the following possibilities:

Brain Tumor

Although amenorrhea (abnormal cessation of menstruation) is usually explained by something else, in rare cases it can be caused by a brain tumor.


In many cases, an underactive or overactive thyroid gland is responsible for the absent menstrual cycles.

Polycystic Ovary Syndrome (PCOS)

In many women with polycystic ovaries, menstruation begins at the normal age.  After a year or two of regular menstruation, the periods become highly irregular and then infrequent.

The Effects Of Overtraining

Many young female athletes in training experience absent menstrual cycles due to low body fat content.  Exercising women with regular menstrual cycles and amenorrheic women who do not exercise excessively demonstrate a clear diurnal rhythm of leptin levels.  Exercising women with amenorrhea lose this normal rhythm, which raises the possibility that this cycle is important for the maintenance of reproductive function.  Leptin levels normally rise during the afternoon and reach a peak in the early hours of the morning, then decline towards dawn.

For some women, simply explaining the need for adequate calorific intake to match energy expenditure results in increased intake and/or reduced exercise, and their menses resume.  For those women in whom no other cause of amenorrhea can be found, but who are unable or unwilling to either increase food intake or decrease the amount of exercise, estrogen replacement therapy is strongly indicated.  Appropriate therapy consists of any estrogen replacement regimen that includes endometrial protection.

Bulimic Tendency

Women with anorexia and/or bulimia often experience amenorrhea as a result of maintaining a body weight that would be too low to sustain a pregnancy.  As a result, as a form of protection for the body, the reproductive system shuts down because it is severely malnourished.

Problems Caused By Being Overweight

Women who are obese often experience amenorrhea as a result of excess fat cells interfering with the process of ovulation.

Concerned or curious about your health?  Try The Analyst™
Symptom Entry
Symptom Entry
Full Explanations
Optional Doctor Review
Review (optional)