Heavy menstrual bleeding

Heavy menstrual bleeding, also called menorrhagia, is regular, excessive blood loss that has an impact on a person’s day-to-day life. It is classified as 80ml or more and/or bleeding for more than 7 days (NICE, 2018).

As this is very difficult to measure clinically other measures are typically used to determine how heavy the bleeding is in each case.

Heavy menstrual bleeding is very common: according to Women’s Health Concern, 1 in 3 women describe their period as ‘heavy’ and 1 in 20 consult their doctor about it each year (Women's Health Concern, 2019). 

It is one of the commonest reasons for a referral to a gynaecologist, with prevalence increasing with age and peaking at the age of 30 to 49 (NICE, 2018).

Blood loss volume is very hard to quantify, therefore a woman will be considered to have heavy menstrual bleeding if her periods last longer than 7 days and/or she experiences the following every 24 to 35 days (NHS, 2018; 2021):

• needs to change a sanitary pad or tampon every hour or two, or to empty a menstrual cup more often than is recommended
• needs to use 2 forms of period product at the same time, like a pad and a tampon
• passes large clots (bigger than 2.5cm, around the size of a 10p coin)
• bleeds through clothing
• bleeds through to bedding during the night
• avoids exercise, daily activities, socialising or work
• feels tired, short of breath and/or lightheaded

Other symptoms may include pelvic/abdominal pain, pressure, and intermenstrual bleeding (bleeding in between periods), the presence or absence of which may indicate the cause of the bleeding and guide diagnosis.

The NHS offers a self-assessment to help determine whether a person’s menstrual bleeding is abnormal or heavy, available at:

In around half of cases of heavy menstrual bleeding, no cause is found; this is called dysfunctional uterine bleeding (NICE, 2018). Every person who menstruates will experience their periods differently, so what’s considered ‘heavy’ for one person might be completely normal for another.

It is important to establish whether the heavy bleeding is something new, and whether – even if it’s abnormally heavy for a particular patient – there is a completely normal and benign cause.

For example, patients might bleed more heavily when their periods first start, after pregnancy, and as they approach menopause. If a patient has been using oral contraceptives, which typically result in lighter menstrual bleeding, and then stops taking them, their periods may get heavier for a while as their hormones adjust.

During that time of adjustment, and when the patient’s cycle returns to what is actually ‘normal’ for them, they might experience heavier bleeding

Diagnosing heavy menstrual bleeding is not always straightforward; blood loss volume is hard to quantify and measure and ‘heavy’ bleeding is subjective.

The first step in assessing a patient is to take a history covering the nature of the bleeding and its impact on the patient’s life, related symptoms, and co-morbidities.

In the absence of any other symptoms, it is not usually necessary to perform any investigations or a physical examination. Medication can be recommended. However, if the patient has related symptoms, a physical examination will typically be needed and after that, blood tests (full blood count, clotting factors) and other investigations (Women's Health Concern, 2019; NICE, 2021).

Tests and investigations include:

• pelvic examination of the vulva, vagina and cervix
• transvaginal ultrasound scan
• endometrial biopsy
• hysteroscopy
• internal swabs to check for infection

It might be useful for the patient to keep a diary of their menstrual bleeding and related symptoms

Patients whose investigations reveal no underlying cause or pathology should be offered levonorgestrel-releasing intrauterine system (LNG-IUS, or simply IUS) as the first-line treatment (NICE, 2021).

IUS – this is a contraceptive coil device inserted into the womb that releases the hormone progesterone into the womb. It acts by thinning the lining of the uterus so there is a lower volume of menstrual blood. Periods therefore become lighter and shorter in duration and may even stop completely after 6-12 months while the IUS is in place (NHS, 2021b).

Combined contraceptive pill – this can be prescribed if a patient declines or is unsuitable for an IUS. Again, this acts on the hormones involved in menstruation, making the uterus lining thinner. Periods become more regular, lighter and shorter in duration (NHS, 2020).

Progesterone contraceptive pill – this can be an option for patients who do not want or cannot have an IUS

References

NHS. Combined pill – Your contraception guide. 2020. https://www.nhs.uk/conditions/contraception/combined-contraceptive-pill/ (accessed 22 February 2022)

NHS. Overview – Heavy periods. 2021. https://www.nhs.uk/conditions/heavy-periods/ (accessed 21 February 2022)

NHS. Intrauterine system (IUS) – Your contraception guide. 2021b. https://www.nhs.uk/conditions/contraception/ius-intrauterine-system/ (accessed 22 February 2022)

NHS. The progestogen-only pill – Your contraception guide. 2021c. https://www.nhs.uk/conditions/contraception/the-pill-progestogen-only/ (accessed 22 February 2022)

National Institute for Health and Care Excellence. Menorrhagia (CKS) 2018. https://cks.nice.org.uk/topics/menorrhagia/ (accessed 21 February 2022)

National Institute for Health and Care Excellence. Heavy menstrual bleeding: assessment and management (NG88). 2021. https://www.nice.org.uk/guidance/ng88/chapter/Recommendations (accessed 22 February 2022)

Women’s Health Concern. Heavy periods. 2019. https://www.womens-health-concern.org/help-and-advice/factsheets/heavy-periods/ (accessed 21 February 2022)