Summary
Read the full fact sheet- Heavy periods are when you lose a lot of blood.
- About one in 4 people have heavy periods.
- Heavy periods can make you feel tired.
- Some health conditions can cause heavy periods.
On this page
What is a heavy period?
A heavy period is when your period lasts more than 8 days or you lose more than 80 mL of blood each cycle.
Signs of heavy periods
It can be hard to know if you have heavy periods, but signs may include:
- bleeding or ‘flooding’ of your period product
- needing to change your period product every 2 hours or less
- needing to change your period product overnight
- blood clots that are larger than a 50-cent piece.
Symptoms of heavy periods
Losing lots of blood through your period can cause you to:
- feel tired, exhausted or dizzy
- look pale
- have cramping and pain in your lower abdomen.
What causes heavy periods?
Heavy periods can be caused by hormonal changes that make the lining of your uterus grow more than usual. When the lining sheds, it creates a heavy period.
Other common causes of heavy periods include:
- endometriosis
- endometrial polyps
- endometrial hyperplasia
- adenomyosis
- fibroids.
Polycystic ovarian syndrome (PCOS) usually causes irregular periods, but if the lining of your uterus thickens you may get heavy periods too.
Getting a diagnosis
It's important to see your doctor if you are worried about heavy periods.
They will ask about your general health and medical history, and may ask to do an internal examination to check your uterus and ovaries (with your consent).
They may also do:
- a pregnancy test
- an iron test
- a cervical screening test
- various blood tests
- an ultrasound.
You can record information about your periods and share it with your doctor. For example, when you get your period, how long it lasts, how heavy it is, and how your periods impact your life.
Treatment options
Treatment options depend on the cause of your heavy periods. Your doctor might recommend:
- medicine, like anti-inflammatory drugs or transexamic acid
- hormonal treatment, like an intrauterine device (IUD), or the pill
- progestins (synthetic forms of the progesterone hormone).
For more serious conditions, they may suggest surgery.
Your doctor may also refer you to a specialist for more tests or further treatment.
More information
For more detailed information, related resources, articles and podcasts, visit Jean Hailes for Women's Health.
Where to get help
- Hallberg L, Högdahl AM, Nilsson L, Rybo G. Menstrual blood loss – a population study. Variation at different ages and attempts to define normality. Acta Obste Gynaecol Scand. 1966;45(3):320–51.
- Heavy menstrual bleeding; assessment & management. NICE guideline [NG88]. March 2018
- Quinn S, Higham J. Outcome measures for heavy menstrual bleeding, Womens Health 2016;(1) 21-26.
- Davies J, Kadir RA. Heavy menstrual bleeding: an update on management. Thromb. Res 2017, 151(1):70-77.
- Kocaoz S, Cirpan R, Degirmencioglu AZ. The prevalence and impacts heavy menstrual bleeding on anemia, fatigue and quality of life in women of reproductive age. Pak J Med Sci. 2019;35(2):365-370. doi:10.12669/pjms.35.2.644.
- Royal College of Obstetricians and Gynaecologists. National heavy menstrual bleeding audit. London: RCOG, 2014.