Understanding Dysfunctional Uterine Bleeding

Author: Jessica Lloyd
Senior Naturopath | BHSc(N) | ISSVD, ISSWSH, BSSM, ATMS

Last reviewed: November 20, 2025

Estimated reading time: 9 minutes

What is DUB?
Symptoms of DUB include:
Why is my bleeding erratic?
Failure to ovulate
- Oestrogen breakthrough bleeding – stable oestrogen (teenagers, PCOS, prolactin, obesity, thyroid)
- Withdrawal/threshold bleeding – low/fluctuating oestrogen (menopause, low body weight, chemo, surgery)
Diagnosing dysfunctional uterine bleeding
The dangers of unusual bleeding
Treating unusual bleeding
Common medical treatments for dysfunctional uterine bleeding include:
Natural medicine treatments for DUB
DUB FAQ
Related Posts
References 3–8

What is DUB?

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).

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.

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.

DUB can occur over one or more cycles or be sporadic. If only one or two cycles occur, with normal cycles resuming, your physician may advise watching and waiting to see if the problem recurs. A DUB pattern requires your and your practitioner’s full attention.

Symptoms of DUB include:

Irregular cycles^1,2
Intermittent and irregular bleeding^1,2
Ranges from light spotting or heavy, continual bleeding (flooding)^1,2

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 maintains the endometrium in the uterus, providing 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 small spirals that act like a control valve to bleed once your period starts, while also providing 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, the endometrium breaks 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 causes 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 postmenopause 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 eventually starts to break down and shed, but without the hormonal cascade’s established pattern, this shedding lacks a clear pattern, even though oestrogen has remained stable.

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 threshold 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 a 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 the 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 are known to affect ovulation
Abnormal body weight

It is key for your physician to determine whether you are ovulating (except in perimenopausal or menopausal women). A set of blood tests will be taken to check hormone levels and assess the involvement of other glands and organs. These tests include thyroid function tests, sex hormone tests, 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 on test results. While natural therapies can help manage some symptoms and support the body, the primary diagnosis of metrorrhagia must be made by your doctor.

Common medical treatments for dysfunctional uterine bleeding include:

No treatment
Iron supplementation
The oral contraceptive pill (OCP) for heavy bleeding
Oestrogen and progesterone therapies (hormone therapy) to re-regulate the endometrium
Physical removal of the endometrium (a D&C)
An IUD with progestogen (Mirena)
Endometrial ablation (laser to remove endometrium)
Hysterectomy

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.

DUB FAQ

What is dysfunctional uterine bleeding (DUB)?

DUB refers to abnormal vaginal bleeding that originates from the uterus but has no identifiable structural or pathological cause, such as fibroids, endometriosis, cancer or pregnancy-related issues. It is most commonly linked to hormonal imbalances that disrupt ovulation and cause unstable endometrial shedding.

What causes the bleeding to be irregular or unpredictable?

Erratic bleeding occurs when oestrogen stimulates the growth of the endometrium but progesterone is not present in stable amounts to hold it in place. Without progesterone from ovulation, the lining becomes fragile and sheds randomly. Dysfunction in the small spiral arterioles of the endometrium can also contribute to unpredictable or heavy bleeding.

How does failure to ovulate lead to DUB?

Ovulation produces progesterone, which stabilises the endometrium. When ovulation does not occur, oestrogen continues to act alone, building up the lining without providing the structure needed for organised shedding. This results in irregular, prolonged, light or heavy bleeding depending on the hormonal pattern.

What is oestrogen breakthrough bleeding?

Oestrogen breakthrough bleeding occurs when oestrogen levels are stable and relatively high, but ovulation does not occur. Without progesterone, the thickened endometrium eventually becomes unstable and sheds in an erratic pattern. This is common in teenagers, people with PCOS, those with high prolactin, obesity or thyroid issues.

What is withdrawal or threshold bleeding?

Withdrawal bleeding appears when oestrogen levels are low or fluctuating, so the endometrium does not grow properly. This leads to a thin, fragile lining that sheds irregularly. It is most common during perimenopause, in individuals with low body weight, or after certain medical treatments such as chemotherapy or surgery.

Who is most affected by DUB?

DUB is most common during times of hormonal instability: shortly after menarche in teenagers and during the perimenopausal years. However, it can occur at any age when ovulation fails. Stress, weight changes, PCOS, endocrine issues, thyroid disorders and certain medications can all play a role.

How is DUB diagnosed?

Diagnosis is based on excluding all other causes of abnormal bleeding. This involves pregnancy testing, cervical examination, pelvic assessment, ultrasounds, hormone testing, thyroid evaluation and menstrual history. Your practitioner must also determine whether ovulation is occurring. In teenagers, clotting disorders such as von Willebrand disease may also be assessed.

Can DUB be dangerous if left untreated?

Untreated DUB can cause iron-deficiency anaemia due to ongoing heavy or unpredictable bleeding. Severe cases may require hospital care or blood transfusion. Long-term unopposed oestrogen also increases the risk of endometrial hyperplasia and endometrial cancer.

How is dysfunctional uterine bleeding treated?

Treatment depends on the underlying cause. Medical options include hormonal therapies, oral contraceptives, iron supplementation, IUDs with progestogen, physical removal of the endometrium (D&C), endometrial ablation or hysterectomy. In some cases, no treatment is required if the issue is mild or self-resolving.

Can natural medicine help with DUB?

Natural therapies can support hormone regulation, reduce heavy bleeding and address root causes such as PCOS, insulin resistance or thyroid imbalances. Herbal medicine, nutritional therapy and metabolic support can be effective adjuncts, but DUB must be medically diagnosed and monitored to rule out serious conditions.

When should I see a doctor for irregular bleeding?

Any abnormal bleeding pattern that persists for more than one or two cycles, is excessively heavy, occurs after sex, appears after menopause, or is accompanied by dizziness, faintness or fatigue requires medical assessment. Pregnancy must always be ruled out, and structural causes must be excluded.

Is DUB the same as heavy periods or menorrhagia?

Not necessarily. DUB refers specifically to irregular or unpredictable bleeding patterns caused by hormonal and ovulatory issues. Menorrhagia describes heavy but cyclical bleeding. The two can overlap, but their causes and treatments may differ.

References^3–8

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