Heavy periods

Also known as heavy menstrual bleeding or menorrhagia

Key points about heavy period bleeding

  • Heavy periods are when you have more bleeding, or longer bleeding, over several menstrual cycles in a row, and the amount of bleeding disrupts your usual activities.
  • The amount of blood lost varies a lot between women, but if you are having heavy periods, see your doctor.
  • Usually there's no underlying cause, but sometimes it may be a sign of a health condition.
  • Treatment will depend on the cause of your bleeding. If a reason for the heavy bleeding is found, eg, a fibroid, it will be treated.
  • Heavy periods can also lead to low blood iron, so you may need a blood test for anaemia.
  • Living with heavy period bleeding can be challenging, so getting good support and taking care of your emotional wellbeing is important.
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The amount of blood lost during a period varies a lot between women. This makes it difficult to give a general description of heavy periods. The amount of blood lost can also vary at different times in your life, including if you have had surgery or take medication.

However, 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:
  • lose more than 5–6 tablespoons of blood (80mls)
  • pass clots that are larger than a 50 cent coin
  • bleed so much that you have to change your pad/tampon every hour
  • have to get up most nights to change your pad/tampon
  • have to put a towel in your bed or use large maternity pads when you sleep
  • bleed through clothing
  • have bleeding that lasts more than 8 days (prolonged bleeding).

Heavy periods can lead to low iron levels and anaemia. These can cause you to feel tired more easily, feel weak or dizzy, be short of breath or have chest pains.

For most women from 25–40 years of age, heavy periods have no underlying cause. It is fairly common for periods to get heavier leading up to the menopause. However, the conditions listed below can sometimes cause heavy periods.

Uterine (womb) related problems

  • Endometrial polyps or uterine fibroids – Endometrial polyps are benign (non-cancerous) growths in your womb (uterus). Uterine fibroids are also found in your womb, but usually bigger than polyps.
  • Endometriosis – The cells that line the inside of your womb are called the endometrium. Endometriosis is where tissue similar to endometrial tissue, which should only be found in the uterus (womb), also grows outside the uterus, eg, on your ovaries or fallopian tubes. This may cause heavy periods, as well as period pain, painful sex and chronic pelvic pain. Read more about endometriosis.
  • Pelvic inflammatory disease (PID) – This is an infection in the pelvic area of your body. Read more about pelvic inflammatory disease.
  • Polycystic ovarian syndrome (PCOS) – This hormonal condition affects how your ovaries work. Symptoms can include irregular or heavy periods, acne, excess facial or body hair, scalp hair loss and weight gain. Read more about PCOS
  • Endometrial hyperplasia – This is when the endometrium is thicker than usual in response to having an excess of oestrogen.

Other medical conditions

Medical treatments

  • Copper intra-uterine device (IUD) – This method of contraception can increase blood loss during periods by almost half (40–50%). 
  • Anticoagulant medicine – These are medicines taken to prevent blood clots.
  • Some medicines used for chemotherapy.
  • Some herbal supplements can affect your hormones and may affect your periods. These include ginseng, ginkgo and soya.

Your doctor might do or advise one or more of the following tests:

  • An examination to see whether the bleeding is coming from your cervix, not your uterus. This is done in a similar way as a cervical smear or HPV screening test.
  • Blood tests to look for anaemia, iron levels, thyroid disease or a bleeding disorder.
  • An ultrasound (scan) of your uterus and ovaries (preferably done vaginally) to detect abnormalities in your uterus, such as polyps or fibroids.
  • cervical sample test in which a swab sample of cells is collected from your cervix and then looked at to see if you have an infection, inflammation or changes in the cells that might be or cause cancer.
  • A sample of the lining of the uterus (biopsy) to see whether there are any precancerous or cancerous changes.

The choice of treatment will depend on the cause of your bleeding. If a reason for the heavy bleeding is found, such as a fibroid, this will be treated.

However, sometimes no cause for heavy periods can be found. In these cases, heavy periods can be treated by medicines or by surgery, with the aim of decreasing the amount of bleeding. Some treatments may stop your periods completely and others may affect your fertility.

Considerations for treatment include your age, general health, whether you require contraception or want to have children. Some treatments are ongoing and others are done one time.

Discuss all your options with your doctor to decide which is best for you.


Examples of medicines to treatment heavy periods include:

Read more about medicines to treat heavy periods.

Surgical treatments

Surgery is only considered when medical treatments have not been effective. Surgical options include: 

Read more about surgery for heavy periods.

Iron deficiency and anaemia

If you have heavy periods each month, one of the key things to watch out for is iron deficiency. One of the most common causes of iron deficiency is prolonged or heavy periods. This can leave you feeling tired and lacking energy. In some cases, this can even lead to anaemia.

Ask your doctor or nurse if you need a blood test to check your ferritin (iron) and full blood count. If your results indicate your iron is low, you may need to also take iron supplements.

If you have low iron, you can also use your diet to help boost your iron levels.  

  • The best source of iron in food is red meat, eg, beef, lamb or venison.
  • Eat plenty of fresh vegetables and fruit. These are high in vitamin C, which helps iron absorption in your gut. 
  • Avoid coffee and caffeinated teas, such as green tea and black tea, as these can decrease the amount of iron your body absorbs. 
  • Read more about iron and iron deficiency.

If the heavy bleeding or low iron is leaving you feeling tired and lacking energy, try to reduce stress, cut down on your caffeine and alcohol, get more exercise and sleep, and give your body healthy food to fuel it. Read more about self-care for fatigue.  

You may also find it useful to track your periods each month using either a symptom diary or period app on your phone. 

It can be difficult managing heavy periods and the way they affect your usual activities. If you find that managing your period each month is stressful or making you feel low, get some support. Talk to friends, family/whānau or ask your doctor for a referral to a counsellor or psychologist for talking therapy.

It can also help to take extra care of yourself during your period. Get some gentle exercise, plenty of sleep and have nourishing food and drinks, such as herb teas. Make time to do something relaxing or something that you know helps your mood. 

Heavy menstrual bleeding(external link) The Royal Australian and New Zealand College of Obstetricians and Gynaecologists


Patient information for heavy periods and bleeding in between periods(external link) Auckland DHB, NZ, 2020
Heavy menstrual bleeding(external link) RANZCOG, 2017
Hysteroscopy(external link) RANZCOG, 2016

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Credits: Healthify editorial team. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Dr Alice Miller, FRNZCGP

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