Types of Menstrual Flows

For most of us, our periods follow a regular schedule; similar to our daily routines. And it is because of this regularity that we know that everything is alright below. Some of us may experience lighter periods, while some may experience heavier periods. The length of the menstrual cycle also varies amongst individuals. So what may be a usual period for you, may not be for another woman. But when our periods deviate from their typical routine, that is when the alarms start ringing. Why? What could be the issue? Is this the new normal? Our menstrual flow tells us a lot about our reproductive health. It is much more than 'our endometrial lining deciding to shed less or more'.

Let's find out about the kinds of menstrual flow and what they mean.


Hypomenorrhoea is very light or scanty periods. Amenorrhoea means absent periods. One of the most worrying aspects of periods is not having them on time. Of course, our minds stray to the most common reason, pregnancy. Other physiologic causes of amenorrhoea could be breastfeeding (lactational amenorrhoea), or perimenopause.

However, there are other reasons for missed periods. The causes of hypomenorrhea and amenorrhoea are pretty similar. Usually, a condition leading to amenorrhoea begins with hypomenorrhea.

Functional Hypothalamic Amenorrhoea (FHA):

What happens in FHA is that a part of the brain (the hypothalamus) stops the secretion of an important hormone, Gonadotropin-Releasing Hormone (GnRH); this completely halts the cascade of hormonal signaling to the pituitary gland (secretes FSH and LH) and ovaries (secretes estrogen). As a result, amenorrhoea occurs. It is known to be 'functional', as the cessation of GnRH secretion is not because of a brain lesion. The fundamental underlying cause of FHA is stress or energy deficit.

The most common causes of FHA are:

  • significant weight loss or being underweight
  • stress-related factors
  • consequences of exercise or practising sports

 Premature Ovarian Insufficiency (POI):

POI occurs when the ovarian function declines before 40 years of age; reaching menopause at an earlier age. The reason for this could be due to:

  • chromosomal abnormalities
  • genetics
  • cancer treatment with chemotherapy or radiation
  • autoimmune disease

Medical Conditions

  • Diabetes Mellitus
  • Thyroid Disease
  • Polycystic Ovarian Syndrome (PCOS)
  • Adrenal insufficiency
  • Hyperprolactinemia
  • Inflammatory Bowel Disease, Celiac disease
  • Infections


  • Birth control pills are the most common medications to cause missed or irregular periods.
  • Anti-epilepsy drugs
  • Anti-psychotics
  • Anti-depressants
  • Cancer chemotherapy


Menorrhagia is heavy menstrual bleeding; flows that last more than seven days and are so heavy that one needs to changes menstrual products by the hour. Dealing with menorrhagia can be exhausting; one has to be hyperaware of any leaks, struggle with the discomfort of clots, and cope with pelvic pain. Menorrhagia can also result in iron deficiency anaemia; resulting in tiredness and fatigue.


Fibroids are benign tumours of the uterine smooth muscle (the middle layer of the 3-layered uterine wall). It is the most common gynaecological tumour in premenopausal women. Fibroids vary in size and location, and they typically do not cause any symptoms. Most of them are usually diagnosed incidentally on an ultrasound (when a pelvic ultrasound is performed for a different reason). However, if a fibroid opts to be symptomatic, its number one symptom would be menorrhagia. Along with menorrhagia, it can cause painful periods or sex, constipation, and reproductive problems.

 Other gynaecological conditions

  • Cervical cancer, endometrial cancer
  • Endometriosis: although the cardinal feature of this condition is painful periods, it can sometimes cause heavy menses
  • Pelvic Inflammatory Disease: infection of the female reproductive tract
  • Pregnancy-associated conditions: miscarriage, ectopic pregnancy

Medical Conditions

  • Bleeding Disorders: a deficiency in a clotting factor can cause heavy periods.
  • Polycystic Ovarian Syndrome: PCOS can cause both light and heavy menstrual bleeding
  • Thyroid disease

Not every change in the menstrual flow has to have an insidious reason behind it. However, it does help to track the menstrual cycle and be aware of when these changes occur. When in doubt, reach out to your doctor, or maybe a friend or sibling; someone with who you are comfortable discussing periods.



  • Roberts, R. E., Farahani, L., Webber, L., & Jayasena, C. (2020). Current understanding of hypothalamic amenorrhoea. Therapeutic advances in endocrinology and metabolism, 11, 2042018820945854. https://doi.org/10.1177/2042018820945854
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  • Hapangama DK, Bulmer JN. Pathophysiology of heavy menstrual bleeding. Womens Health (Lond). 2016 Jan;12(1):3-13. doi: 10.2217/whe.15.81. Epub 2015 Dec 23. PMID: 26695831; PMCID: PMC5779569.

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