The menstrual cycle is a complex biological process regulated by hormones, which plays a key role in a woman's reproductive health. Any deviations from the normal rhythm, duration, or nature of bleeding may indicate disorders that require attention. Understanding the causes of these disorders is critical for proper diagnosis and effective treatment.
What is a menstrual cycle disorder?
Menstrual cycle disorders encompass a wide range of conditions in which the regularity, frequency, duration, or volume of menstrual bleeding deviate from the norm. These include:
- Amenorrhea (absence of menstruation)
- Oligomenorrhea (infrequent menstruation)
- Polymenorrhea (frequent menstruation)
- Hypomenorrhea (scanty menstruation)
- Hypermandrory/Menorrhagia (heavy and/or prolonged menstruation)
- Metrorrhagia (acyclic bleeding)
- Menometrorrhagia (prolonged and heavy acyclic bleeding) [1]
These conditions can significantly impair quality of life and be a sign of serious health problems.
Hormonal imbalance and its impact
Hormones are the conductors of the menstrual cycle, and their imbalance is one of the most frequent causes of disorders. Particular attention should be paid to thyroid function.
The role of the thyroid gland
The close relationship between thyroid function and menstrual disorders has long been known. A 2024 study showed that women with thyroid dysfunction (both subclinical and overt hypo- or hyperthyroidism) are significantly more likely to experience various menstrual irregularities [1].
For example, in hypothyroidism (insufficient production of thyroid hormones), heavy and prolonged menstruation (menorrhagia) as well as infrequent menstruation (oligomenorrhea) may be observed. In hyperthyroidism (excessive production), frequent menstruation (polymenorrhea) or even its complete absence (secondary amenorrhea) are more common [1].
This is why thyroid function must be checked for any menstrual cycle disorders. Conversely, the pattern of the menstrual cycle should be carefully evaluated in women with diagnosed thyroid dysfunction [1].
Menstrual migraine: the connection with the cycle
Migraine is a common neurological disease that is significantly more prevalent in women. There are two main subgroups of menstrual migraine:
- Pure menstrual migraine (PMM): attacks occur exclusively during the perimenstrual period (directly before, during, or immediately after menstruation).
- Menstrually related migraine (MRM): attacks occur both in the perimenstrual period and in other phases of the cycle [2].
MRM accounts for 20-25% of all migraine cases in women and is often characterized by greater severity and disability compared to other types of migraines [2]. Hormonal fluctuations, especially the drop in estrogen levels before menstruation, are considered a key factor in the development of menstrual migraine [2, 4].
Even exogenous estrogens used, for example, in in vitro fertilization (IVF), can increase the frequency and severity of headache attacks in women, especially those who already suffer from migraines. This underlines the sensitivity of migraines to estradiol fluctuations [3].
Treatment of menstrual migraine can be challenging because attacks are often more severe, prolonged, and less responsive to standard therapy than non-menstrual episodes [4, 5]. However, new approaches are emerging, such as targeted therapy directed against calcitonin gene-related peptide (CGRP). These methods show promising results in reducing the overall migraine burden, although the perimenstrual component may remain relatively resistant [4].
Other factors affecting reproductive health
In addition to hormonal disruptions and migraines, there are other conditions that can affect the menstrual cycle or be closely related to reproductive health.
Recurrent pregnancy loss
Recurrent pregnancy loss (repeated pregnancy losses) is a severe condition affecting about 1% of couples trying to conceive [7]. Although not a direct disorder of the menstrual cycle, it is often associated with profound systemic problems that can also affect cycle regularity. The pathophysiology of recurrent pregnancy loss is diverse and may include hematological, endocrinological, immunological, and genetic factors [7]. Identifying these causes requires a comprehensive evaluation, which may also shed light on potential menstrual cycle disorders.
Chronic anemia
Heavy menstrual bleeding (menorrhagia) is one of the frequent causes of chronic anemia, especially iron deficiency anemia. Anemia, in turn, can worsen overall health and act as both a consequence and an indirect factor influencing cycle regulation. When evaluating chronic anemia, it is important to consider the history of menstrual bleeding, as this may be a key element in diagnosis [8].
When to see a doctor and the importance of diagnosis
If you notice any changes in your menstrual cycle—whether it is irregularity, a change in duration, the volume of bleeding, or the onset of severe pain—it is extremely critical to consult a doctor. Timely diagnosis allows the underlying cause of the disorder to be identified and appropriate treatment to be prescribed.
A comprehensive approach, including medical history collection, physical examination, laboratory tests (including thyroid hormones [1]), and instrumental studies, will help establish an accurate diagnosis. Remember that cycle disorders are not just an inconvenience, but a signal from the body about potential problems requiring professional evaluation.
Sources
- [1] Characteristics of the menstrual cycle in women with and without thyroid disease. (Cureus, 2024) https://pubmed.ncbi.nlm.nih.gov/39036195/
- [2] Clinical characteristics of pure menstrual migraine and menstrually related migraine: a cross-sectional online survey study. (BMC neurology, 2026) https://pubmed.ncbi.nlm.nih.gov/42249327/
- [3] Migraine in women undergoing fertility treatment: a prospective study. (Headache, 2026) https://pubmed.ncbi.nlm.nih.gov/42175659/
- [4] Beyond triptans in menstrual migraine: the emerging role of CGRP-targeted therapy. (Expert opinion on emerging drugs, 2026) https://pubmed.ncbi.nlm.nih.gov/42288968/
- [5] Progress and evolution direction of menstrual migraine research: a bibliometric analysis from 1994 to 2026. (Frontiers in medicine, 2026) https://pubmed.ncbi.nlm.nih.gov/42445136/
- [7] Modern management of recurrent miscarriage. (The Australian & New Zealand journal of obstetrics & gynaecology, 2019) https://pubmed.ncbi.nlm.nih.gov/30393965/
- [8] How I approach chronic anemia. (Hematology. American Society of Hematology. Education Program, 2012) https://pubmed.ncbi.nlm.nih.gov/23233579/
Disclaimer: The information provided in this article is for reference purposes only and cannot replace professional medical advice. Always consult a qualified specialist for the diagnosis and treatment of any medical conditions.