Heavy periods

How much is heavy bleeding?

It's difficult to define exactly what a heavy period is because it varies from woman to woman. Heavy for one woman may be normal for another.

Most women will lose less than 16 teaspoons of blood (80ml) during their period, with the average being around 6 to 8 teaspoons.

Heavy menstrual bleeding is defined as losing 80ml or more in each period, having periods that last longer than 7 days, or both.

However, it's not usually necessary to measure blood loss. Most women have a good idea of how much bleeding is normal for them during their period and can tell when this changes.

A good indication that your periods are heavy is if you:

• are having to change your sanitary products every hour or two
• are passing blood clots larger than 2.5cm (about the size of a 10p coin)
• are bleeding through to your clothes or bedding
• need to use two types of sanitary product together – for example, tampons and pads

What causes heavy periods?

In about half of women with heavy menstrual bleeding, no underlying reason is found. But there are several conditions and some treatments that can cause heavy menstrual bleeding.

Some conditions of the womb and ovaries can cause heavy bleeding, including:

• fibroids – non-cancerous growths that develop in or around the womb and can cause heavy or painful periods
• endometriosis – where the tissue that lines the womb (endometrium) is found outside the womb, such as in the ovaries and fallopian tubes (although this is more likely to cause painful periods)
• adenomyosis – when tissue from the womb lining becomes embedded in the wall of the womb; this can also cause painful periods
• pelvic inflammatory disease (PID) – an infection in the upper genital tract (the womb, fallopian tubes or ovaries) that can cause symptoms like pelvic or abdominal pain, bleeding after sex or between periods, vaginal discharge and fever
• endometrial polyps – non-cancerous growths in the lining of the womb or cervix (neck of the womb)
• cancer of the womb – the most common symptom is abnormal bleeding, especially after the menopause
• polycystic ovary syndrome (PCOS) – a common condition that affects how the ovaries work; it causes irregular periods, and periods can be heavy when they start again

Other conditions that can cause heavy periods include:

• blood clotting disorders, such as Von Willebrand disease
• an underactive thyroid gland (hypothyroidism) – where the thyroid gland does not produce enough hormones, causing tiredness, weight gain and feelings of depression
• diabetes

Medical treatments that can sometimes cause heavy periods include:

• an IUD (intrauterine contraceptive device, or "the coil") – this can make your periods heavier for the first 3 to 6 months after insertion
• anticoagulant medication – taken to prevent blood clots
• some medicines used for chemotherapy
• some herbal supplements, which can affect your hormones and may affect your periods – such as ginseng, ginkgo and soya

Seeing a GP and further tests

Your GP will start by asking you about your heavy bleeding, any changes to your periods and any other symptoms you have, like bleeding between your periods or period pain.

All women who have heavy periods should be offered a blood test to check for iron deficiency anaemia.

The GP may also suggest a physical examination or refer you for further tests to try to find out if there's an underlying cause for your heavy periods. Further tests may include:

• other blood tests
• an ultrasound scan
• a hysteroscopy – where a narrow telescope with a light and camera at the end is passed into the womb through the vagina to examine the inside of the womb

Read more about diagnosing heavy periods.

Treating heavy periods

There are various treatment options for heavy periods. These depend on what's causing your heavy periods, your general health and your preferences.

They include:

• an intrauterine system (IUS) – a small device that contains the hormone progestogen is inserted in your womb by a medical professional (often the first treatment offered)
• medicines without hormones – such as tranexamic acid or non-steroidal anti-inflammatory drugs (NSAIDS)
• medicines with hormones – such as the combined oral contraceptive pill or progestogen tablets
• endometrial ablation – a procedure to remove the lining of the womb
• myomectomy – surgery to remove fibroids
• uterine artery embolisation – a procedure to shrink fibroids
• hysterectomy – surgery to remove to the womb

Read more about treating heavy periods.