Heavy periods: how to tell when it is too much, and why
According to the NHS, your period is probably too heavy if you change a pad or tampon every 1 to 2 hours, it lasts more than 7 days, you pass clots larger than about 2.5 cm or you bleed through your clothes and bedding. Heavy periods are often normal for a given woman, but they can be caused by fibroids, endometriosis, adenomyosis, pelvic inflammatory disease, bleeding disorders or some medicines. If they get in the way of your life or come with severe pain and bleeding between periods, see a doctor.
- According to the NHS, many women have heavy periods (menorrhagia), and for them this can be normal.
- Signs that bleeding is too heavy: changing a pad/tampon every 1–2 hours, needing two products at once, a period lasting more than 7 days, clots larger than about 2.5 cm.
- Bleeding can be heavier when periods first start, after pregnancy and in the run-up to the menopause.
- Possible causes are conditions of the womb and ovaries (fibroids, endometriosis, adenomyosis, pelvic inflammatory disease), bleeding disorders and some medicines.
- The NHS notes that, rarely, heavy periods can be a sign of womb cancer – another reason not to ignore them.
How do I know my period is too heavy?
There is no exact measure in millilitres you can check at home, so the NHS gives practical signs. According to these, your period may be heavy if:
- you change your pad or tampon every 1 to 2 hours, or empty your menstrual cup more often than is recommended;
- you need to use two products together, for example a pad and a tampon;
- your period lasts more than 7 days;
- you pass clots larger than about 2.5 cm;
- you bleed through your clothes or bedding;
- you avoid daily activities such as exercise, or take time off work because of your period;
- you often feel tired or short of breath.
Is it normal to have heavy periods?
According to the NHS, many women have heavy periods, and for them this can be completely normal. Bleeding can be heavier at certain times of life – when periods are just starting, after pregnancy and as the menopause approaches.
A useful guide is not only the amount but also change: if your periods have always been like this and do not bother you, this is probably your normal. If, however, they have become heavier than before, last longer or come with new symptoms, that is a different situation and worth checking.
This does not mean you have to put up with it. The NHS notes that heavy periods do not always need treatment, but treatment can help if they get in the way of your daily life.
What can cause heavy periods?
The NHS groups the possible causes like this:
- Conditions of the womb or ovaries – fibroids, endometriosis, adenomyosis, pelvic inflammatory disease and the syndrome known until now as PCOS (polycystic ovaries), which the NHS now calls PMOS.
- Conditions that make you bleed more easily – for example von Willebrand disease.
- Some medicines and treatments – certain anticoagulants and chemotherapy.
According to the NHS, in rare cases heavy periods can be a sign of womb cancer. This is not a reason to panic, but a reason not to put off a consultation if you also have other worrying symptoms.
What tests will I have?
According to the NHS, if treatment from your GP does not help or they suspect an underlying condition, you will usually be referred for tests or to a specialist. You may have blood tests to check for conditions such as iron deficiency anaemia – a common consequence of prolonged heavy bleeding that explains tiredness and breathlessness.
Before your appointment, it is useful to keep notes: how many days your period lasts, how often you change products, whether there are clots and bleeding between periods. This makes it easier for the doctor to judge whether it is normal or something that needs investigating.
When should you see a doctor?
The NHS recommends booking an appointment with a doctor if:
- heavy periods are affecting your life;
- you have had heavy periods for some time;
- you have severe pain during your periods;
- you bleed between periods or after sex;
- you have heavy periods together with other symptoms, for example pain when peeing, pooing or having sex.
What treatment might I be offered?
According to the NHS, your GP may suggest some contraceptives such as an intrauterine system (IUS) or the combined contraceptive pill, a medicine to reduce bleeding such as tranexamic acid, or prescription anti-inflammatory painkillers such as mefenamic acid or naproxen.
If this is not enough, a specialist may discuss with you endometrial ablation (removing the lining of the womb), removal of fibroids if they are thought to be causing the bleeding, or a hysterectomy – complete or partial removal of the womb. These are decisions of varying seriousness, and the choice depends on the cause, your age and your plans for children.
Frequently asked questions
How many days of bleeding count as too many?
According to the NHS, a period that lasts more than 7 days is one of the signs of heavy bleeding.
Why do I feel constantly tired with heavy periods?
The NHS lists tiredness and breathlessness as signs of heavy periods, and blood tests can check for iron deficiency anaemia as an underlying cause.
Can a medicine I already take make my periods heavier?
Yes. According to the NHS, certain anticoagulants (blood thinners) and chemotherapy medicines can cause heavier periods – tell your doctor what you are taking.
Sources
- NHS – Heavy periods – last reviewed by the NHS: 19 September 2024
Informational article retold in our own words from the sources listed. It does not replace a consultation with a doctor; in an emergency call 112. If you spot an inaccuracy, write to [email protected].