You may have heavy periods if you lose a lot of blood during your periods, pass large blood clots or your periods last more than 7 days.
It's not always clear why some women get heavy periods. Sometimes it's linked to conditions like fibroids or endometriosis.
Common treatments for heavy periods include contraceptives and medicines to help reduce the amount of blood you lose.
It's difficult to define exactly what a heavy period is because it varies from woman to woman. Heavy for 1 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.
But 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 2
- 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 2 types of sanitary product together (for example, tampons and pads)
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 a high temperature
- 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
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 medicine – 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
There are various treatment options for heavy periods. These depend on what's causing your heavy periods, your general health and your preferences.
- 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
Page last reviewed: 07-06-2018
Next review due:07-06-2021