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What causes bleeding between periods?

There are many different causes of bleeding between periods. Some may not be anything to worry about, but seek medical advice if you're concerned.

Hormonal contraceptives

Irregular bleeding, such as bleeding between periods, is common during the first few months of starting hormonal contraception, such as the:

If you're concerned about bleeding or it lasts longer than a few months, you should seek medical advice.

You may also bleed between periods if you:

Other causes

Some other causes of bleeding between periods include:   

  • taking the emergency contraceptive pill
  • injury to the vagina – for example, from having penetrative sex
  • recently having an abortion – seek medical advice if you're bleeding heavily
  • sexually transmitted infections (STIs) such as chlamydia – it's a good idea to get tested if you've recently had unprotected sex with a new partner
  • recently having a miscarriage
  • reproductive hormones not working normally – this is common in women approaching the menopause or in women with polycystic ovary syndrome (PCOS)
  • stress
  • vaginal dryness
  • harmless changes to the neck of the womb (cervix) – this may be called cervical ectropion or cervical erosion
  • cervical cancer – if you're aged 25 to 64, you should be having regular cervical screening tests to detect any changes to your cervix; even if you're up-to-date with screening tests, you should see a GP about irregular bleeding, particularly bleeding after sex, to eliminate the possibility of cervical cancer
  • womb (uterus or uterine) cancer – this is more common in post-menopausal women and most cases of endometrial cancer are diagnosed in women over the age of 50; see a GP if you're over 40 and have bleeding between periods to eliminate the possibility of uterine cancer
  • vaginal cancer or vulval cancer
  • cervical or endometrial polyps – non-cancerous (benign) growths in the womb or the lining of the cervix
  • fibroids

When to seek medical advice

If you're concerned about bleeding between periods, you should:

A healthcare professional will talk to you about your symptoms. Depending on your situation, they may suggest doing some tests, such as:

To diagnose some conditions, you may need an examination, such as:

  • a speculum examination – a smooth, tube-shaped tool (a speculum) is inserted into your vagina to examine your vagina and cervix
  • an internal examination of your vagina with gloved fingers (bimanual examination)

Find out the answers to more questions about women's health

Further information