Heavy Periods
What’s that?! Blood clots in your menstrual blood

What’s that?! Blood clots in your menstrual blood

You may be alarmed the first time you see clots in your menstrual blood, but for most individuals who menstruate, occasional period blood clots are normal, and this is usually nothing to be worried about.

However, if you are experiencing a large number of blood clots and your periods are causing discomfort, embarrassing situations or painful symptoms, it is time to take action.

Experiencing frequent blood clots during your period

It is not unusual to experience blood clots during your periods from time to time, as your body forms them naturally to prevent too much blood from being lost. However, if you regularly have large blood clots the size of a 10p piece (or larger), it is worth visiting your GP to get checked out.

You may be suffering from heavy periods, otherwise known as menorrhagia. This is a recognised medical condition that affects 1 in 5 women in the UK[1], and it can have a major impact on those suffering from it. In addition to heavy bleeding and pain, symptoms may include prolonged periods, anaemia, bleeding between periods and fatigue, to name a few.[2]

Various factors can cause clots in your menstrual blood

Blood clots caused by menopausal changes

It is common for women to experience all kinds of changes to their periods around the time of their menopause. This can vary from a shorter cycle to prolonged, heavy periods with severe pain and blood clots.[3] Learn more about how menopause can affect your periods.

Polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a hormone imbalance which can result in the excess production of androgens, leading to inflammation and heavy menstrual bleeding. These heavy periods may be accompanied by blood clots.

Fibroids (myomas)

Fibroids can cause blood clots during menstruation. The cause of fibroids is not known, but hormone production is known to play a part. They usually occur later in life, with women who are overweight or of Afro-Caribbean descent at higher risk of developing them.[4] Read about why some women develop fibroids, and others do not.

Normal periods and blood clots

Whether or not you can establish a clear cause, a high number of large blood clots during your period is abnormal and should be examined.

If you are concerned about heavy menstrual bleeding and blood clots during your period, it is advisable to make an appointment with your GP. The #BeBloodyConfident period toolkit has been created to equip you for these conversations. Track your cycle using our period diary, and fill in this questionnaire to prepare yourself for your GP appointment.


[1] – National Women’s Health Resource Center. Survey of women who experience heavy menstrual bleeding. Data on file; 2005. Cooper J, et al. A randomized, multicentre trial of safety and efficacy of the NovaSure system in the treatment of menorrhagia. J Am Assoc Gynecol Laparosc. 2002; 9:418-428; https://bit.ly/3SdUuJr [last accessed 26/06/2023]

[2] – Heavy periods (menorrhagia) | Health Information | Bupe UK. [online] Available at: https://www.bupa.co.uk/health-information/womens-health/menorrhagia. [last accessed 26/06/2023]

[3] – NHS (2019). Symptoms – Menopause. [online] NHS. Available at: https://www.nhs.uk/conditions/menopause/symptoms/. [last accessed 26/06/2023]

[4] – Eltoukhi, H.M., Modi, M.N., Weston, M., Armstrong, A.Y. and Stewart, E.A. (2014). The health disparities of uterine fibroid tumors for African American women: a public health issue. American Journal of Obstetrics and Gynecology, [online] 210(3), pp.194–199. doi:https://doi.org/10.1016/j.ajog.2013.08.008. [last accessed 26/06/2023]

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