Dysfunctional uterine bleeding (DUB) (spotting, mid-cycle bleeding)

Dysfunctional uterine bleeding

Dysfunctional uterine bleeding (DUB) is abnormal vaginal bleeding coming from the uterus that is not caused by any other identifiable uterine condition (like cancer or menstrual bleeding).​1​

Irregular bleeding is often caused by hormonal imbalances affecting the endometrium, with the result being irregular shedding of the endometrium, causing erratic bleeding. A lack of ovulation is a feature.​1​

Spotting and irregular bleeding is most common in teenagers around the time of the start of periods (menarche), but also around menopause, but if a woman is not ovulating, anovulatory cycles can occur at any age, with a range of causes including PCOS, stress, and obesity. ​1​

DUB can occur over one or more cycles or be sporadic. If only one or two of these cycles occurs, with normal cycles once again resuming, usually watching and waiting to see if the problem recurs may be advised by your physician. A pattern of DUB needs you and your practitioner’s full attention.​1​

Symptoms of DUB include​1,2​:

  • Irregular cycles
  • Intermittent and irregular bleeding
  • Ranges from light spotting or heavy, continual bleeding (flooding)

Why is my bleeding erratic?

Growth of the endometrial lining stimulated by oestrogen is tempered in a healthy cycle by progesterone in the luteal phase (second half of the menstrual cycle after ovulation).

Progesterone keeps the endometrium inside the uterus to provide nutrients to a fertilised egg (if one exists). Once progesterone drops off (when your body discovers you are not pregnant), a menstrual period (bleed) occurs.

If progesterone is lacking, the endometrial lining – blood – can ‘fall out’ randomly. The hormonal triggers are not being set off to keep the endometrial lining in place so it becomes unstable.

Part of this process is the development of special little spirals that act like a control valve for bleeding once your period starts, but also provide a blood supply to the growing endometrium.

If these spirals (arterioles) don’t develop properly, there is no control mechanism in place for the bleeding once your period starts, but also no blood supply to the endometrium.

Without progesterone, this results in the endometrium breaking down sporadically. Dysfunction of these spirals can also result in heavy bleeding as described in the heavy periods (menorrhagia) article.

Failure to ovulate

One of the causes of erratic spotting or bleeding is a lack of ovulation, but the cause of the ovulatory failures are many and varied. Oestrogen is the main player, with irregular bleeding the result of low levels (as observed after menarche in teenagers and at menopause in older women).

Oestrogen breakthrough bleeding – stable oestrogen (teenagers, PCOS, prolactin, obesity, thyroid)

If you aren’t ovulating, you are not producing progesterone, so the endometrium, fed by oestrogen (oestrogen makes things grow – boobs, bums, endometrium), starts to lose itself after a while and becomes unstable without its friend progesterone to keep it in its place. This is known as oestrogen breakthrough bleeding.

As described above, the endometrium after a while starts to break down and shed, but this has no real pattern to it without the pattern developed by the hormonal cascade, even though oestrogen has remained stable and present.

The more oestrogen you have, the more menstrual blood you have. Failure to ovulate can happen when a form of oestrogen (oestradiol, E2) isn’t around in sufficient amounts to trigger a surge of LH (luteinising hormone), which triggers ovulation.

This occurrence is more common in teenage girls, who have immature hormonal systems in place. It should naturally resolve a few months or even a year or two after periods begin, if this is the case, though heavy bleeding may result.

Other reasons that high and stable oestrogen levels prevent ovulation include polycystic ovarian syndrome (PCOS), high prolactin levels (found during lactation), obesity, and thyroid problems.

Withdrawal/threshold bleeding – low/fluctuating oestrogen (menopause, low body weight, chemo, surgery)

If you are not ovulating and have low or variable oestrogen levels, you won’t have progesterone tempering the oestrogen. Low levels of E2 oestrogen are commonly observed just before menopause. This is known as withdrawal bleeding or thresholding bleeding.

The endometrial lining becomes thinner and can shed irregularly, and eventually spotting or no bleeding will be all you see as menopausal levels of E2 are all that’s left.

If the pattern deviates from this, another condition may be present such as fibroids. This occurrence is called threshold or withdrawal bleeding because E2 is not reaching its goals.

Diagnosing dysfunctional uterine bleeding

Diagnosing DUB is a process of excluding other problems of reproductive and pelvic organs, and a pregnancy test.

  • Age is important – older and younger women have higher incidence of DUB without ovulation
  • Pregnancy must be ruled out
  • Check the cervix for abnormalities
  • Check the uterus size and shape (fibroids and adenomyosis can change the shape/size)
  • Family or personal history of bleeding disorders
  • Menstruation history – irregular cycles since onset of menstruation can indicate other issues
  • Hormonal contraceptives or hormone therapy can cause irregular bleeding
  • Vaginal and abdominal examination to check for pain or tenderness (DUB does not cause abdominal or vaginal pain)
  • High or severe stress – impacts conjoined hormone systems
  • Other conditions present known to affect ovulation
  • Abnormal body weight

It is important for your physician to determine whether or not you are ovulating (except in perimenopausal or menopausal women) and a barrage of blood tests will be taken to check hormone levels to figure out the involvement of other glands and organs. These tests include the thyroid, sex hormones, pap smear, and ultrasounds.

The testing for DUB is extensive because it needs to be – figuring out the cause can take some time and effort. Teenage girls may be tested for von Willebrand disease.

The dangers of unusual bleeding

Untreated DUB can result in iron deficiency due to ongoing and sometimes very heavy bleeding, causing dizziness, fatigue and faintness.

Heavy bleeding can sometimes require a blood transfusion and hospital care. Oestrogen without progesterone to temper it presents an increased risk of endometrial cancer.

Treating unusual bleeding

Treatment of DUB will be based almost entirely based on the results of medical testing. While the use of natural therapies can help in managing some of the symptoms and support the body, primary diagnosis of metrorrhagia must be done by your doctor.

Common medical treatments for dysfunctional uterine bleeding include:

Natural medicine treatments for DUB

Your natural medicine practitioner will address the underlying issues that may be present, particularly with PCOS and insulin resistance, after a clear diagnosis and extensive testing has been completed.

Managing heavy bleeding can be done very well with herbal medicines, as can regulating hormones and supporting optimal function of organs, including the ovaries. Your case will be managed on an individual basis, dependent on the test results.


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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)