Why does my menstrual cycle change and go wrong?

You regularly track your menstrual cycle. You know the length of your menstrual cycle, the length of your period, feel your ovulation, and discern the symptoms of your PMS. But recently, you've noticed that your menstrual cycle is changing and seems to be out of whack : its length is changing, your symptoms are changing, your periods are variable... Why is your menstrual cycle changing and what are the consequences? Discover the reasons and solutions in this article.

How does a menstrual cycle work?

The menstrual cycle is a natural process that occurs every month in menstruating people of reproductive age. It is organized into four phases:

• Menstrual phase (also called “period” or “menstruation”): it generally lasts between 2 and 7 days,
• Follicular phase during which an egg matures in the follicles of the ovaries. It begins at the same time as the menstrual phase and generally lasts 14 days,
• Ovulatory phase : this corresponds to the release of the egg by the ovaries and lasts, for most women, between 24 and 48 hours,
• Luteal phase : this last phase begins at the same time as the ovulatory phase and corresponds to the body's preparation for implantation in the event of fertilization, in particular by producing the endometrium (uterine lining). It lasts 14 days.

The four phases of the menstrual cycle are orchestrated by hormones and induce different symptoms and signs, more or less visible, in the body of menstruating people. When the egg is not fertilized, the body expels it along with the uterine lining: this is your period and a new cycle begins!

Irregular cycles or period disruption: how to tell the difference?

Before delving into the causes and consequences of a change in your menstrual cycle, it's important to define exactly what constitutes a change in your cycle. A change in your menstrual cycle doesn't mean you have irregular cycles; there's a distinction to be made between the two.

Irregular cycles are cycles that do not correspond to the "norm" of menstrual cycles. These are longer menstrual cycles (exceeding 32 days), or shorter cycles (less than 24 days ) or those with significant variations (exceeding 9 days of difference). We have offered you articles on these different cycle peculiarities that can be completely benign or be symptomatic of a more serious problem.

A cycle that changes abruptly, as we are talking about it today, is a cycle that has stabilized for several months / years and then suddenly changes for about 6 months. It is not impossible that your cycle changes punctually (one cycle is different) for benign reasons that we will review later (stress, travel, etc.). It is when this change seems to settle in and repeat itself, for several cycles, that it is important to question yourself.

Consulting your doctor, your general practitioner or your gynecologist , could then be a good way to understand what is happening and to carry out additional examinations, if necessary.

What are the menstrual disorders we are talking about?

When we talk about the disruption of rules, we are talking, for example, about changes:

• Cycle length: longer or shorter cycles
• Regularity of cycles: periods that suddenly become irregular
• Period flow: very heavy or very light periods
• Period duration: longer or shorter periods

These disorders must be long-term (several cycles in a row) to require a consultation. Note that even if you had a cycle outside the average (very short for example) and its disruption brings it into the average (it is closer to 28 days), it may be worth consulting.

What causes a change in your menstrual cycle?

The menstrual cycle is particularly sensitive. It can vary for many reasons and be a symptom of various conditions, some more troublesome than others. This is why it can be helpful to track your menstrual cycle and don't hesitate to consult your doctor or gynecologist if you have any concerns.

Hormonal changes

Menstrual cycles are controlled by hormones , particularly progesterone and estrogen, whose levels naturally vary enormously. In this context, hormonal changes or even hormonal imbalances can cause sudden changes in your menstrual cycles.

1. Puberty

During puberty, there is a significant increase in sex hormones, such as estrogen and progesterone. The body begins releasing eggs, which triggers the menstrual cycle. Initially, egg release may be irregular, which can make the first few years of menstruation rather unpredictable. Puberty typically occurs in young women between the ages of 10 and 15.

2. Menopause

Menopause is marked by a gradual decline in estrogen. As this decline progresses, ovulation becomes more erratic and may eventually cease, leading to irregular cycles and then the complete cessation of menstruation. Menopause typically occurs between the ages of 45 and 55.

3. Polycystic Ovary Syndrome (PCOS)

Women with PCOS often have a hormonal imbalance characterized by elevated androgen (male hormone) levels and insulin resistance. This hormonal abnormality can impede the ovulation process, leading to irregular cycles or even the absence of ovulation (anovulation).

4. Thyroid diseases

The thyroid produces hormones essential for regulating metabolism, growth, and development. It also influences sex hormones and can affect the regularity of the menstrual cycle.

In the case of hypothyroidism (when the thyroid is underactive), the release of thyroid hormone is reduced. This can lead to elevated levels of prolactin, a hormone that can inhibit ovulation.

Hyperthyroidism (overactive thyroid) can speed up metabolism and disrupt the balance of sex hormones, leading to irregular cycles.

His way of life

Did you know? Your lifestyle can affect your menstrual cycles. As we just saw, hormones are at work regulating cycles. However, different habits can affect your hormones and disrupt your menstrual cycle.

1. Stress

In situations of stress, whether temporary or chronic, the body secretes several hormones, such as adrenaline, noradrenaline, and cortisol. These hormones can interact with the hormones that regulate the menstrual cycle, thus altering it more or less abruptly. Have you been feeling anxious lately? Check out our collection of articles dedicated to mental health and stress, including our anti-stress routine:

See the anti-stress routine

2. Sudden weight variation

Significant and rapid weight gain, like significant and rapid weight loss, can abruptly alter the menstrual cycle. Several factors come into play:

• In the case of significant weight gain: obese people are likely to secrete more androgens (male hormones) through adipose tissue, which can disrupt their hormones and cycle. In addition, insulin resistance , sometimes caused by significant weight gain, can create hormonal imbalances.
• In the case of significant weight loss: in the event of a significant caloric deficit , the production of sexual hormones decreases: the body goes into pause. Cycles become rarer or even disappear (amenorrhea). Similarly, too low a percentage of body fat can lead to hormonal imbalance.

3. Intense physical exercise

Regular and intense exercise can affect the menstrual cycle, and some women may experience a temporary cessation of their periods, a phenomenon known as functional hypothalamic amenorrhea.

This can be explained by different factors:

• Physical activity level: When physical activity levels are very high, it can disrupt hormonal signals between the brain and the ovaries – and it is the hormones produced by the brain (LH and LSH) that are responsible for menstrual cycles.
• Calorie deficit: If you burn more calories than you consume due to intense and prolonged training, this can lead to a calorie deficit. Sex hormone production decreases: the body goes into pause mode . Cycles become rarer or even disappear (amenorrhea).
• Physical and mental stress: Physical stress, such as frequent and intense workouts, can increase levels of cortisol, a stress-related hormone. High cortisol levels can also affect the menstrual cycle.
• Body Fat Percentage: A low body fat percentage, often associated with intensive exercise, can disrupt the hormonal balance necessary for a regular menstrual cycle.

4. Travel

Because travel can be stressful and jet-lagged, the body and hormones can be thrown into disarray in the months following a major trip.

Diseases, medications and medical interventions

Certain illnesses, medications, and medical procedures, due to their influence on hormones, can cause menstrual cycles to become disrupted . If you are concerned about this, do not hesitate to discuss it with your doctor, specialist, or gynecologist.

1. Diseases that affect the menstrual cycle

We mentioned earlier that Polycystic Ovary Syndrome (PCOS) is a health condition that affects the regularity of cycles. But it's not the only one. Other conditions include:

• Uterine fibroids: These are non-cancerous tumors that develop in the uterus. Depending on their location and size, they can be painful and cause heavy periods, menstrual pain, and irregular cycles.
• Endometriosis: This is a condition in which tissue similar to the uterine lining grows outside the uterus, sometimes into the surrounding organs. It can cause severe pelvic pain, heavy bleeding, and irregular cycles.
• Blood clotting disorders: Some clotting disorders, such as von Willebrand disease, can cause heavy and prolonged menstrual bleeding. Your flow then changes significantly.
• Eating disorders (ED): Eating disorders such as anorexia and bulimia, due to the caloric deficiencies and deficits they cause, can disrupt the menstrual cycle due to hormonal changes and nutritional deficiencies. Many menstruating anorexic people experience amenorrhea.
• Chronic diseases: Certain chronic diseases, such as diabetes and kidney disease, can influence the menstrual cycle.
• Gynecological cancer: Cancers of the female reproductive organs, such as uterine or ovarian cancer, can cause changes in the menstrual cycle, such as abnormal bleeding.

⚡Don't panic. As we've seen, there are many reasons why your menstrual cycle can suddenly be disrupted (slow down, speed up, stop, etc.), and illnesses aren't the only ones! However, it's important to consult your doctor if you notice a change in your menstrual cycles so that you can get a diagnosis and answers to your questions.

2. Hormonal contraceptives

Hormonal contraceptives (hormonal pill, hormonal IUD, or hormonal implant) work by interfering with the menstrual cycle. They release hormones into the body to block sperm access and prevent the egg from attaching to the uterus. Generally, they regulate the body's hormone levels themselves and create an artificial menstrual cycle. This is why they disrupt the length of the menstrual cycle and disrupt natural periods (different flow, different duration).

3. Psychiatric medications

Some psychiatric medications can affect a woman's menstrual cycle due to their effects on hormones and neurological systems. It all depends on the type of medication, the dose prescribed and taken, the duration of treatment, and your specific circumstances.

Here are some examples, but don't forget to consult your doctor if you experience sudden, unexplained changes in your cycle: they are your best advisor and will be able to examine your medical situation and provide you with answers.

• Antidepressants and anti-anxiety medications: These psychiatric medications, including selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs), may affect the levels of hormones involved in the menstrual cycle. This can lead to changes in periods, such as heavier or lighter bleeding, menstrual irregularities, or even missed periods.
• Antipsychotics: Some antipsychotics, particularly those that act on dopamine receptors, can also affect the menstrual cycle , even producing false-positive results on a pregnancy test. Hormonal imbalances induced by these medications could disrupt regular menstruation.
• Mood stabilizers: These medications, used for bipolar disorder, such as lithium and divalproex, have the uncommon side effect of affecting the menstrual cycle.

4. Chemotherapy

Chemotherapy, a medical treatment often offered in cancer treatments to stop the growth of cancer cells, can significantly disrupt the menstrual cycle. It all depends on the treatment, its duration, and you.

Complete cessation of periods (amenorrhea), irregular cycles, lengthening or shortening of the duration of cycles or even early menopause: all of these symptoms can occur during chemotherapy.

If you are currently undergoing treatment or are currently undergoing treatment and notice any changes in your menstrual cycle, do not hesitate to discuss this with your primary care physician and oncologist. They will be able to answer your questions and adjust your treatment or, if that is not an option, offer options for managing these effects.

5. Hysterectomy

A hysterectomy is a surgical procedure that removes the uterus. It is most often performed for medical reasons (endometriosis, cancer). It results in the cessation of periods, but not necessarily of menstrual cycles : if you are not menopausal and the ovaries are not affected, their function will persist until natural menopause. You may therefore experience symptoms related to your cycles without seeing any bleeding.

Note that in cases of fallopian tube ligation, menstruation continues even though ovulation stops. In this case, menstruation corresponds to the expulsion of the endometrium (the uterine lining that develops in the uterus during the luteal phase) and not to the expulsion of the unfertilized egg.

Pregnancy and breastfeeding

This may seem like a no-brainer, but the final cause that can disrupt your menstrual cycle is none other than... pregnancy. Once the egg is fertilized and attached to the uterine wall, the sex hormones responsible for the proper functioning of the menstrual cycle work to stop menstrual cycles and facilitate pregnancy.

Once the baby is born, choosing to breastfeed most often has the effect of blocking the restart of the menstrual cycle: prolactin, which has the role of boosting milk production, also has the capacity to block the menstrual cycle.

Finally, after a pregnancy, whether or not continued with breastfeeding, menstrual cycles may change compared to what you experienced before (longer, shorter, more or less painful symptoms, etc.). This phenomenon of changes in postpartum menstrual cycles is also found in other situations: some women report that after taking hormonal contraception for a long time, their natural menstrual cycles have changed (duration, symptoms, flow, etc.).

💡Note: In certain very specific cases (particularly when pregnancy is denied), menstrual cycles may continue despite fertilization and pregnancy, until the end of the pregnancy, in the ninth month.

What are the consequences for your menstrual cycle?

The consequences of a suddenly disrupted menstrual cycle can be both physical and mental. That's why it's important to consult a healthcare professional if you notice your cycles suddenly changing.

On the physical level

On a physical level, the consequences of a disrupted and altered menstrual cycle on one's menstrual cycle are first of all the resulting menstrual irregularity . Longer or shorter cycle, variable flow... The cycle becomes difficult to predict.

Furthermore, the symptoms of premenstrual syndrome (PMS) are either amplified or more varied: strong and unpredictable menstrual pain, swollen and painful breasts, migraines, digestive problems, fatigue, water retention... If we thought we knew our bodies until now, the cards are reshuffled and each cycle can bring its share of symptoms.

Finally, and this is often what brings women to consult, menstrual cycles that change suddenly can be synonymous with difficulties in conceiving a child or even infertility . This is firstly because ovulation and the fertility window are less stable than in the context of regular menstrual cycles. Secondly, because some of the causes that lead to the disruption of periods and the menstrual cycle can be synonymous with difficulties in conceiving (notably diseases such as endometriosis and PCOS).

On the emotional level

From an emotional perspective, a sudden disruption in menstrual cycles can cause anxiety and stress in menstruating people who experience it. This can be due to a number of reasons:

• Feelings of uncertainty: Not knowing when your period will start can be stressful and difficult to manage, especially if your period is accompanied by complicated symptoms.
• Hormonal fluctuations and PMS amplification: We were talking about this on a physical level, but the amplification of PMS and associated symptoms can also be mental. Anxiety and depressive episodes related to the menstrual cycle can become more severe.
• Difficulty conceiving – if that’s what you want: Having difficulty conceiving a child can be particularly stressful, and even guilt-inducing in some cases.

Natural Treatments for Premenstrual Syndrome >

Is it serious if my menstrual cycle is disrupted?

The menstrual cycle is particularly sensitive to hormonal fluctuations and thus to all the constraints that the body of menstruating people may encounter on a daily basis. Menstrual cycle disruption can therefore be symptomatic of many causes, some more serious than others. A stressful event in your life (moving, separation, birth, bereavement) can be the cause, as can more disabling and serious illnesses such as endometriosis, PCOS or gynecological cancer.

How to manage and react to sudden change?

If you experience a sudden change in your menstrual cycle, the first thing to do (and it's easy to say, it's true) is not to panic. Fluctuations in your menstrual cycle over the course of a month can occur for many benign and natural reasons—a change in your menstrual cycle can occur over several cycles.

The second thing to do is to take the time to observe your cycle and track it for several months to see the differences. You can use a period tracking app to help you note the changes.

If this observation highlights a sudden change in your menstrual cycle that seems to be ongoing, we recommend that you consult your general practitioner or gynecologist. They will take the time to question you and cover your entire medical profile to conduct additional tests if they deem it necessary.

Finally, note that you can consult a doctor for reassurance as soon as you notice a change in your menstrual cycle. However, your healthcare provider may ask you to track your menstrual cycle over a few months to confirm the changes—unless they notice other symptoms in addition to the sudden change in your menstrual cycle.