What Is Oligomenorrhea

Oligomenorrhea is one of the most common menstrual disorders and appears to have been increasing over recent years.1 Menstrual patterns can vary greatly from individual to individual and throughout the menstruating years. It is very normal to experience menstrual irregularities during times of hormonal change like puberty and perimenopause, but sometimes infrequent periods need investigating.

The definition of oligomenorrhea is having ‘irregular and inconsistent menstrual flow’. Irregular and inconsistent menstrual flow can be defined as menstrual cycles that are longer than 35 days, meaning you may only menstruate between 4-9 times a year.2

This article discusses what oligomenorrhea is, what causes it and what to expect from a visit to the doctor. Thankfully, there are different available ways of diagnosing the condition as well as treatments you may be offered.


Menstrual patterns (periods) can vary greatly throughout the menstruating years - individual differences and life stages often account for this variation, but sometimes other factors are at play that need to be investigated and treated to restore normal functioning. It is also important to be familiar with your own menstrual cycle and what is ‘normal’ for you in order to distinguish when something might be wrong. 

Causes of oligomenorrhea

Usually, oligomenorrhea is caused by endocrine disorders, but there are many possible causes that vary in their frequency of incidence. Some of these causes include:

Signs and symptoms of oligomenorrhea

The main signs of oligomenorrhea will be a change in the duration of the menstrual cycle and the history of previous menstrual cycles. Infrequent periods (without the presence of obvious causes such as pregnancy or menopause) is the main sign of oligomenorrhea. Others signs and symptoms that may present include:

Management and treatment for oligomenorrhea

The way oligomenorrhea will be managed or treated will depend on the cause. These include options such as:

  • Lifestyle changes: if stress or weight is suggested as a factor in your diagnosis, diet changes may be necessary to maintain a ‘normal’ weight and mental health issues and stress may need to be addressed with interventions such as stress relief techniques, therapy or medication
  • Treating underlying conditions: any conditions that are causing oligomenorrhea will need to treated, such as medication to treat hyperthyroidism
  • Hormonal therapy: if a hormonal imbalance is suggested as the cause, contraceptive pills may be used to regulate your hormones, for example, in polycystic ovarian syndrome
  • Surgery: if tumours are causing this condition then surgical removal may be required

Diagnosis of oligomenorrhea

To reach a diagnosis of oligomenorrhea the first step will be to gather a detailed history of the menstrual cycle.

Other symptoms that could indicate certain health conditions and oligomennorhoea as a possible side effects to any medications that are being taken will also be considered.

Usually a physical examination will be performed and could include the following:

  • Abdominal examination: Involves feeling for fluid in the tummy and any unusual lumps or tenderness in the area
  • External general physical examination: Looking for any unusual signs such as irregular hair growth
  • Rectovaginal examination: An internal examination of the vaginal walls looking for signs of inflammation or unusual discharge
  • Vaginal speculum examination: Using a speculum to look into the vagina 

Blood tests may be performed to find the cause of oligomenorrhea and may involve testing various different hormone levels including:

  • Follicle-stimulating hormone (FSH): Initiates normal ovarian function
  • Thyroid-stimulating hormone (TSH): A hormone secreted by the thyroid gland which has different metabolic actions
  • Luteinising hormone (LH): Relevant when diagnosing polycystic ovarian syndrome
  • Testosterone: This hormone may be increased in some disorders
  • HbA1C: This test looks for long-term blood glucose levels
  • CA-125: A marker for possible ovarian cancer

You may also be asked to undergo some other investigations to establish the cause of oligomenorrhea including: 

Risk factors

Risk factors for developing oligomenorrhea will be underlying hormonal imbalances and metabolic disorders. Certain medications may also increase the risk of developing oligomenorrhea.

Factors that may be easier for an individual to control include weight management (avoiding being under or overweight) and avoiding excessive exercise. Managing underlying conditions such as diabetes will also reduce your risk of developing oligomenorrhea.


The complications of oligomenorrhea will depend on the cause but can include:

  • Infertility: particularly where reduced menstruation is caused by problems affecting the function of the ovaries such as PCOS, anatomic issues, inflammation or fibrosis
  • Endometrial hyperplasia: untreated oligomenorrhea could lead to a condition of hyperplasia where cells reproduce rapidly and promote tissue growth
  • Endometrial cancer: this could occur after the development of hyperplasia
  • Cardiovascular issues: if oestrogen levels are low due to ovarian dysfunction then the cardioprotective effects of oestrogen will be reduced, increasing the risk of heart problems
  • Osteoporosis: again a decrease of oestrogen leads to an increased risk of osteoporosis
  • Neuropsychiatric conditions


How can I prevent oligomenorrhea

You may not be able to prevent oligomenorrhea as sometimes health conditions are beyond our control. However, being aware of the condition will help you to notice if you have any symptoms that may indicate a problem. Paying attention to your menstrual cycle and the length of it will help you notice any changes. Keeping a healthy weight and checking any medications you use will also help to eliminate the possible causes of oligomenorrhea, making it easier to treat and prevent.

How common is oligomenorrhea

Approximately 13.5% of the population will experience oligomenorrhea and up to 10% of cases will be caused by polycystic ovarian syndrome.2

When should I see a doctor

Make an appointment with your doctor if you are noticing changes to your periods such as irregular or infrequent periods. If you are experiencing any pain, unusual discharge or abnormal hair growth you should promptly visit your doctor. 


Menstrual irregularities are not uncommon as regular menstrual cycles can become disrupted by many different factors such as stress, illness and other lifestyle changes. If infrequent periods become the norm for you then it is important to investigate the cause to rule out certain conditions. Sometimes oligomenorrhea can be the result of serious problems, but often the cause is less serious but is still important to investigate and treat to avoid any future issues with your fertility, reproductive health and mental wellbeing.


  1. He, Yilei, et al. “Prevalence of Oligomenorrhea among Women of Childbearing Age in China: A Large Community-Based Study.” Women’s Health, vol. 16, Jan. 2020, p. 174550652092861. DOI.org (Crossref). Available from: https://doi.org/10.1177/1745506520928617.
  2. Riaz, Yumna, and Utsav Parekh. “Oligomenorrhea.” StatPearls, StatPearls Publishing, 2023. PubMed. Available from:  http://www.ncbi.nlm.nih.gov/books/NBK560575/.
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Victoria Ward

BSc, Herbal Medicine,University of Lincoln

Experienced Medical Herbalist BSc (Hons) and former nurse, highly knowledgeable about healthcare and medicinal plants. I’m especially interested in skin care and gut health. Regular blogger for my own website and freelance article writer. I enjoy writing both creative, ghostwriting and medical writing. Passionate about country life, have two horses and a collie dog.

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