Irregular periods: what are the causes and solutions?

In theory, a woman has a regular period every 4 weeks, i.e. every 28 days. But in real life, women's menstrual cycles are all different and vary enormously. Menstruation is often irregular, arriving a few days early or late. In fact, menstrual periods vary in length.

What are irregular periods?

In reality, irregular menstruation occurs when thelength of a period alternates between long and short cycles, or when the abundance varies from one cycle to the next. This happens to almost all women, especially during the first few cycles. Indeed, the first menstrual periods often rhyme with a dysregulated hormonal system, which can even last for several years. It's also very common during pre-menopause. But this phenomenon can happen at any time, as a number of factors come into play. Menstruation is said to be irregular when :

  • there are less than 20 days or more than 40 days between each period
  • the duration between each menstrual flow is highly variable
  • the duration of the menstrual flow itself is highly variable from one menstrual cycle to the next
  • theabundance of blood loss is highly variable from one cycle to the next: abundant one cycle, then light the next

That's why we recommend menstrual briefs, which you can wear on a daily basis and which will protect you from unpleasant surprises.

What causes irregular periods?

Irregular flow is due to a disturbance in the hormonal system, and there are many possible causes in women. They should not be confused with spotting!

A healthy lifestyle

Lifestyle has a phenomenal impact on our body and all its mechanisms, especially the hormonal machine. When the body and its resources are subjected to stress, the reproductive system is among the first to be deregulated to prioritize other vital functions.

Among the culprits of unhealthy living are the following factors:

  • lack of sleep, increased fatigue
  • Stress, anxiety, depression: any stressful situation can affect your menstrual flow.
  • Jet lag, or jet lag, which can disorientate our internal biological clock: the body struggles to return to its natural rhythm, temporarily disrupting the production of melatonin, the sleep hormone, as well as reproductive hormones.
  • Excessive consumption of drugs: alcohol, tobacco, cannabis, but also coffee in high doses
  • Weight extremes: too little body fat stops hormone secretion, and can even lead to amenorrhea, while too much weight is responsible for overproduction of estrogen, disrupting menstrual flow.
  • Similarly, sudden, excessive weight gain or loss: eating disorders such as bulimia and anorexia nervosa can also be the cause.

The more you combine several of these factors, the more irregular your periods are likely to be.

Intensive sports activities

Too much sport puts a great deal of pressure on the body. This pressure can then block or disrupt the system, reducing production of the hormones responsible for regular menstruation. High-level sportswomen are therefore regularly affected by unpredictable periods or evenamenorrhea.

Taking medication

>Taking medication or hormone treatments can also influence the regularity of menstrual periods. Substances that increase prolactin levels in the body can alter the functioning of the female cycle. Taking or stopping a hormone-based contraceptive, such as hormonal IUDs or progestin-only pills, can reduce menstrual blood loss or even eliminate it altogether.

Uterine disease

But irregular periods can also reveal more serious problems, such as the following gynaecological conditions or disorders:

  • Polycystic ovary syndrome(PCOS), a syndrome that also causes acne and excessive hair growth, due to an increase in testosterone.
  • Endometriosis, known for irregular menstruation associated with pain and heavy blood loss
  • Polyp or fibroma
  • Benign tumor or even cancer of the uterus
  • A thyroid orhypothalamus disorder

When irregular menstrual bleeding is associated with other symptoms of illness, it is essential to consult your gynecologist or health care professional.

When are irregular periods normal?

There are, however, cases in which it is very common, even normal, to observe an abnormal menstrual flow. Let's find out.

First periods in adolescence

The first bleeding at puberty is often irregular and anarchic: this is perfectly normal! In fact, it takes around one to two years for hormone production to regulate, for the female cycle to settle down and for the uterus to find its natural rhythm. The system needs to find its cruising speed! Beware of pregnancy, however, as an irregular cycle during puberty does not mean no ovulation: it's possible to get pregnant as soon as your periods start!
However, if after 2 or 3 years, menstruation has not become regular, it may be worth asking your GP or health professional to rule out any gynaecological disorders. A pill may also be prescribed to give the flow a certain regularity.

Irregular periods after childbirth

Afterchildbirth, the body has undergone a major upheaval, and menstruation may be delayed depending on a number of factors, including breastfeeding. After the lochia (removal of the last placental debris) and the return of childbirth (the first post-delivery period), menstrual flow may take several months to return to its natural rhythm. The abundance of menstrual flow may also be affected by pregnancy. It's important to remember, however, that fertility can return 2 weeks before menstruation, so you need to be vigilant when having unprotected intercourse or without contraception (pill or other). The absence or delay of a period may mean you are pregnant!


The perimenopause, the period approaching menopause in women around the age of 45, is also known to be a time of major hormone changes: the system begins to function in slow motion during the pre-menopause, coming to a definitive halt at menopause. This is whenmenstruation, ovulation and fertility come to adefinitive halt! Until this fateful moment arrives, menstruation may be irregular.

When should you seek medical advice for irregular periods?

It's a good idea to consult your healthcare professional for treatment in the following cases of irregular menstruation:

  • If you notice major variations in the length or abundance of menstrual flow, and this phenomenon is associated with other symptoms
  • A lack of menstrual bleeding, a slow onset of menstrual bleeding or even a false anniversary period can all be signs of a pregnancy in the making: a pregnancy test will confirm or refute this hypothesis.
  • On the other hand, an irregular cycle can make it difficult to predict ovulation for a planned baby: although this is not necessarily a sign of infertility, you can consult your gynaecologist to make sure you're on the right track.

You can also take advantage of alternative therapies to help you relax and eliminate stress, which can aggravate menstruation: acupuncture, osteopathy, yoga, meditation...

FAQs on irregular periods

When is a period irregular?

Irregular periods occur when menstrual cycles are separated by less than 20 days or more than 40 days. The length and abundance of bleeding also vary considerably from one cycle to the next.

Is it normal to have irregular periods?

Without necessarily giving cause for concern, an abnormally irregular menstrual flow can be due to a number of causes: from simple hormonal contraception, to a rushed lifestyle, to more severe gynaecological conditions, it's important to seek advice if you're worried or if your irregular periods are accompanied by other symptoms.

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