Causes of mid-cycle spotting and bleeding

Mid-cycle Spotting

Metrorrhagia is the medical name for bleeding between menstrual periods, with the cause of the bleeding determining the flow – spotting, irregular, random, heavy, flooding, or a combination of these.

Causes of mid-cycle spotting or bleeding are many and varied, so getting an accurate, timely diagnosis is essential just in case it’s something serious. It also helps determine whether what is happening is normal for you.

Spotting or bleeding might look like a pinky smudge in your underwear when you ovulate, which might be completely normal for you, but if all of a sudden you start bleeding after sex, you have something else to deal with.

Bleeding after sex

Bleeding after sex, use of sex toys, or tampons is abnormal and means cells are being more easily burst than they should be.

Rough sex can cause bleeding, but this is usually accompanied by pain, and you know why it happened. Cuts and tears from sex heal up quickly and don’t tend to recur, at least not in the same way each time.

Determining the cause

Any irregular bleeding has a cause; there is no such thing as ‘trivial metrorrhagia’. ​1–3​

While some women get spotting during ovulation, or just before the onset of their periods (which is considered normal for those women), unusual bleeding needs to be investigated by a physician quickly, and treated according to the results.

Any vaginal/uterine bleeding in postmenopausal women needs to be treated as suspicious.

Irregular bleeding and spotting is one of the indicators of ovarian, endometrial and cervical cancers, so ruling those out is an important step if bleeding starts to happen where it didn’t before.

Treating unusual spotting or bleeding

The treatment for unusual spotting or bleeding will depend on the cause, so check the list and try to establish what it isn’t to whittle down the list (for example, if you are definitely not pregnant, scratch that off the list).

Then, go through and check each set of symptoms and narrow it down a bit more so you can have a more thorough chat with your doctor at your appointment. (Make it now.)

Causes of bleeding or spotting between periods

  1. Pregnancy – implantation bleeding, placental malfunction, or molar pregnancy
  2. Ectopic pregnancy – this is a medical emergency
  3. Dysfunctional uterine bleeding (DUB) (oestrogen breakthrough bleeding, threshold bleeding)
  4. Endometrial hyperplasia (an overgrowth of period-producing cells)
  5. Endometrial cancer
  6. Cervical polyps
  7. Cervical abnormalities
  8. Cervical eversion/ectropion (the delicate mucous-producing cells from the neck of your cervix start growing on the outside, easily burst with contact, e.g. penis, toys, tampons)
  9. Cervical dysplasia and cancer
  10. Ovulation bleeding (hormonal surge)
  11. Ovarian cysts (can burst)
  12. Ovarian cancer
  13. Vaginitis (inflammation of cells, ultimately resulting in bleeding)
  14. Desquamative inflammatory vaginitis (DIV)
  15. Cervicitis (inflammation of cervical cells, resulting in bleeding)
  16. Hormonal contraception and drugs (causing hormone disturbances that cause breakthrough bleeding)
  17. Intrauterine device (IUD)
  18. Coagulation/blood disorders
  19. Underweight (malnutrition)
  20. Polycystic ovarian syndrome (PCOS)
  21. Poor oestrogen metabolism (relative oestrogen excess, causes proliferation of period-producing endometrial cells)
  22. Thyroid conditions
  23. Adrenal gland conditions (congenital adrenal hyperplasia (CAH))


  1. 1.
    Madhra M, Fraser IS, Munro MG, Critchley HOD. Abnormal uterine bleeding: advantages of formal classification to patients, clinicians and researchers. Acta Obstet Gynecol Scand. Published online April 30, 2014:619-625. doi:10.1111/aogs.12390
  2. 2.
    Tsolova AO, Aguilar RM, Maybin JA, Critchley HOD. Pre-clinical models to study abnormal uterine bleeding (AUB). eBioMedicine. Published online October 2022:104238. doi:10.1016/j.ebiom.2022.104238
  3. 3.
    Zhang CY, Li H, Zhang S, et al. Abnormal uterine bleeding patterns determined through menstrual tracking among participants in the Apple Women’s Health Study. American Journal of Obstetrics and Gynecology. Published online February 2023:213.e1-213.e22. doi:10.1016/j.ajog.2022.10.029

Jessica Lloyd - Vulvovaginal Specialist Naturopathic Practitioner, BHSc(N)

Jessica is a degree-qualified naturopath (BHSc) specialising in vulvovaginal health and disease, based in Melbourne, Australia.

Jessica is the owner and lead naturopath of My Vagina, and is a member of the:

  • International Society for the Study of Vulvovaginal Disease (ISSVD)
  • International Society for the Study of Women's Sexual Health (ISSWSH)
  • National Vulvodynia Association (NVA) Australia
  • New Zealand Vulvovaginal Society (ANZVS)
  • Australian Traditional Medicine Society (ATMS)