Missed Periods? Here Are Five Possible Reasons Why

Menstruation is a complex physiological process. It provides valuable insights into our hormonal health, offering important information about overall well-being each month. While occasional irregularities in our cycle can be completely normal, persistent changes, such as late or completely missed periods, warrant investigations to find the underlying cause. Below, we explore five potential causes for late or missed periods.

1. Pregnancy: An Obvious Culprit

Pregnancy is a common reason for a missed period. Human chorionic gonadotropin (hCG), a hormone produced during pregnancy, inhibits menstruation. The developing fetus keeps reproductive hormone levels elevated, preventing the shedding of the uterine lining.  hCG can be measured in both blood and urine tests, but can be falsely negative if taken too early. 

2. Polycystic Ovary Syndrome

(PCOS): A Common Hormonal Disorder: PCOS affects approximately 10% of women of reproductive age. This disorder can lead to irregular menstrual cycles due to hormonal imbalances, particularly elevated levels of androgens and insulin, which disrupt ovulation. Some women with PCOS may not cycle for many months at a time. Other common symptoms associated with PCOS include weight gain, facial hair growth, and acne. 

3. Thyroid Disorders: The Role of Thyroid Hormones

Thyroid hormones play an important role in regulating reproductive hormones and therefore regulating the menstrual cycle. Both hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid) can lead to menstrual irregularities. Most commonly hypothyroidism will cause irregular or heavy bleeding, while hyperthyroidism can cause less frequent, and lighter periods. Blood tests can assess thyroid hormone levels and assist in diagnosis. 

4. Perimenopause: The Transition to Menopause

Perimenopause is the period of life as a woman transitions into menopause. It usually begins in the 40’s, though it can start earlier for some. During this time, hormonal fluctuations and less responsive ovaries can lead to erratic ovulation and irregular cycles. Women tend to experience missed cycles later in the perimenopausal transition, with more frequent cycles happening earlier in the transition. Experiencing other symptoms such as hot flashes, night sweats, mood or sleep changes can be indications of perimenopause. 

5. Hypothalamic Amenorrhea: Stress and Lifestyle Factors

Hypothalamic amenorrhea occurs when the brain reduces hormonal output to the ovaries, affecting hormone production and ovulation. The most common causes of hypothalamic amenorrhea  include significant weight changes, excessive exercise or prolonged high stress. Managing stress, and addressing lifestyle factors such as diet, and activity levels are needed to restore a regular cycle. 

Conclusion

Consistently missed or late menstrual cycles can indicate underlying health conditions. It is crucial to understand why to maintain reproductive health. While the five causes outlined above are common, other factors such as type 2 diabetes, pituitary adenomas, rheumatoid arthritis, and other autoimmune conditions may also play a role. A thorough investigation is often necessary to determine the underlying cause and treat it effectively. 

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