What Your Irregular Cycle Is Telling You
Your period was always predictable – and now it is not. Or perhaps it has never been regular. Cycles that are too short, too long, too heavy, too light, or absent altogether are your body’s way of signalling that something in the hormonal orchestra is off. At our practice in Zürich Seefeld, I investigate menstrual irregularities thoroughly because they often provide valuable clues to underlying health conditions.
What Is a “Normal” Menstrual Cycle?
A normal cycle ranges from 21 to 35 days, with menstruation lasting 2 to 7 days. Regularity – meaning your cycle length varies by no more than 7-9 days from month to month – is more important than the exact number. Irregularity can mean cycles shorter than 21 days (polymenorrhoea), longer than 35 days (oligomenorrhoea), absent periods for three or more months (amenorrhoea), or cycles that vary unpredictably in length.
Common Causes of Irregular Periods
PCOS (Polycystic Ovary Syndrome): The most common cause of irregular periods in women of reproductive age. PCOS involves hormonal imbalance (elevated androgens), metabolic dysfunction (insulin resistance), and often – but not always – polycystic ovaries on ultrasound.
Thyroid dysfunction: Both hypothyroidism and hyperthyroidism disrupt the menstrual cycle. Hypothyroidism typically causes heavy, prolonged periods; hyperthyroidism can cause light or absent periods.
Stress and HPA axis dysfunction: Your body prioritises survival over reproduction. Under significant stress, the hypothalamus suppresses GnRH (gonadotropin-releasing hormone), which disrupts the entire hormonal cascade controlling your cycle. This is called hypothalamic amenorrhoea.
Perimenopause: In the years before menopause, fluctuating hormone levels cause cycles to become irregular – shorter, longer, heavier, lighter, or skipped entirely.
Underweight or excessive exercise: Low body fat and high physical stress can suppress ovulation, particularly in athletes and women with restrictive eating patterns.
Hyperprolactinaemia: Elevated prolactin levels (from pituitary adenoma, medications, or other causes) suppress ovulation and can cause irregular or absent periods along with breast discharge.
Premature ovarian insufficiency: Early decline in ovarian function before age 40, causing irregular periods, menopausal symptoms, and reduced fertility.
Our Diagnostic Approach
Timing matters in hormone testing. I check FSH, LH, oestradiol, and prolactin on day 2-5 of the cycle; progesterone on day 19-21 (to confirm ovulation); testosterone, free testosterone, DHEA-S, and SHBG for androgen assessment; thyroid panel; fasting glucose and insulin; and AMH (anti-Müllerian hormone) when ovarian reserve is relevant. Pelvic ultrasound evaluates ovarian morphology and uterine structure.
What We Do: Restoring Cycle Regularity
Treat the underlying cause: PCOS management, thyroid optimisation, stress reduction, or prolactin management – treatment depends entirely on diagnosis.
Support ovulation: Nutrients that support ovulatory function include zinc, vitamin D, B6, inositol (particularly effective in PCOS), and vitex.
Address insulin resistance: In PCOS, improving insulin sensitivity with diet, exercise, inositol, and sometimes metformin can restore regular ovulation.
Stress and lifestyle: Ensuring adequate caloric intake, managing exercise load, and addressing chronic stress to support hypothalamic function.
Hormonal support when needed: Bioidentical progesterone to support the luteal phase, or other hormonal interventions as appropriate.
Conclusion
Irregular periods are not something to ignore or simply suppress with hormonal contraception. They are a diagnostic opportunity – a chance to identify and address underlying hormonal, metabolic, or thyroid conditions. If your cycle is irregular, I encourage you to book a consultation at our practice in Zürich Seefeld for a thorough investigation.
