Irregular menstrual cycle: is this the start of perimenopause?

We have all experienced an irregular menstrual cycle. But how can we know if it is a symptom of something wrong or just a sign of a new stage in our life? We explain all about it.

What is an irregular menstrual cycle

Every woman has her rhythm. Nonetheless, a menstrual cycle should last between 2 and 7 days, with a maximum flow of 80ml of blood loss per day. This should happen every 21 to 35 days (Mayo Clinic, n.d.). An irregular menstrual cycle consists of a change in what is usual to that person. For instance:

  • Decreased or increased flow
  • Variation in duration
  • Early or late periods
  • Spotting between irregular cycles

Causes of an irregular menstrual cycle

Menstrual cycles can become irregular at any time during a woman’s life –from puberty to menopause. Some of its most frequent causes include (Pinkerton, 2020):

Irregular menstrual cycle: is this the start of perimenopause?

Why does an irregular menstrual cycle happen during perimenopause?

Hormonal changes are the cause of irregular cycles during the menopause. Progesterone and oestrogen prepare the ovaries and uterus for pregnancy each month. Through fluctuations and lower production levels of these hormones, the ovaries and uterus no longer operate in the same manner and consequently, women lose their usual period rhythm and begin experiencing an irregular menstrual cycle (Pinkerton, 2020). Overall, the perimenopausal stage can start up to 10 years before your last period occurs. Toward the end, this process stops altogether. Hence, an irregular cycle tends to signify female infertility (Dumont et al., 2017).

Menstrual cycle changes during perimenopause

At the onset of perimenopause, an irregular menstrual cycle first begins with periods longer than 7 days on average. Moreover, there can be limited or increased flow (even hemorrhages). Soon afterward, women experience brown spotting or brown discharge between periods (Pinkerton, 2020). In time, late periods become more prominent. During the following 2 to 4 years, there can be absent menstrual periods for over 8 weeks at a time. When 12 months go by since the last period, menopause is considered to have begun (Dumont et al., 2017).

Associated symptoms

Limited hormones are bound to cause anomalies throughout the body. Accordingly, perimenopause can generate a variety of symptoms (Dumont et al., 2017):

  • Insomnia
  • Headaches
  • Breast tenderness
  • Hot flushes
  • Night sweats
  • Fatigue
  • Depression
  • Anxiety
  • Changes in sex drive
  • Vaginal dryness
  • Memory changes


When an irregular menstrual cycle affects the normal functioning of the body, it should be treated by a specialist. Some standard tests involved in this process are blood tests, ultrasounds, and magnetic resonance imaging (MRI). Initial treatment may include pain medication, vitamins, and minerals, such as vitamin D, calcium, and iron (in cases of anemia) (Pinkerton, 2020). Moreover, there are hormone-based treatments to halt excessive bleeding. The most common options include (Armeni et al., 2016):

  • Oral or injected contraception
  • Oestrogen
  • Progesterone
  • Hormone intrauterine devices
  • Tranexamic acid
  • Uterine surgery


Perimenopause symptoms are typically uncomfortable. So, this is a prime time to practice self-care. It is also important to consider making changes, such as (Mintziori et al., 2015):

  • Quitting smoking, reduce alcohol and coffee consumption.
  • Calculate your BMI and aim to keep in the heavy weight zone for your height.
  • Engage in regular physical exercise.

This transition is as normal as puberty. The goal for you and any woman remains to take care and feel your best. References Armeni, E., Lambrinoudaki, I., Ceausu, I., Depypere, H., Mueck, A., Pérez-López, F. R., Schouw, Y.T. van der, Senturk, L.M., Simoncini, T., Stevenson, J. C., Stute, P., & Rees, M. (2016). Maintaining postreproductive health: A care pathway from the European Menopause and Andropause Society (EMAS). Maturitas, 89, 63–72. Dumont, A., Bendris, N., Dewailly, D., Letombe, B., & Robin, G. (2017). Perimenopausia. EMC - Ginecología-Obstetricia, 53(4), 1–15. Mayo Clinic. (n.d.). Ciclo menstrual: qué es normal y qué no. Mintziori, G., Lambrinoudaki, I., Goulis, D.G., Ceausu, I., Depypere, H., Erel, C. T., Pérez-López, F.R., Schenck-Gustafsson, K., Simoncini, T., Tremollieres, F., & Rees, M. (2015). EMAS position statement: Non-hormonal management of menopausal vasomotor symptoms. Maturitas, 81(3), 410–413. Pinkerton, J.V. (2020, diciembre). Sangrado uterino anormal debido a disfunción ovulatoria. Manual MSD.