There are lots of different reasons you might experience abnormal uterine bleeding.

Let’s look at some of the causes.

Abnormal uterine bleeding is an umbrella term used by doctors to describe a multitude of different irregularities in the experience of a period. One of the ways doctors diagnose abnormal uterine bleeding is by using the acronym PALM COEIN. Each letter stands for a different diagnosis.

These diagnoses fall into two broad categories: PALM being structural and COEIN being non-structural causes. Structural causes can be seen on ultrasound scans or biopsies whereas non-structural causes cannot.

PALM COEIN

Structural causes

Polyp
Adenomyosis
Leiomyoma
Malignacy

Non-structural causes

Coagulopathy
Ovulatory dysfunction
Endometrial
Iatrogenic
Not otherwise classified

What do each of these letters mean?

Polyps 

Uterine polyps are small growths that grow on the uterus lining. They are usually benign (not cancer) and are also known as endometrial polyps.

Prevalence up to 12%. Prevalence is the frequency or commonness of this cause in people with abnormal uterine bleeding. Up to 12% of people who experience abnormal uterine bleeding may have polyps.

Adenomyosis 

The tissue that normally lines the uterus (endometrial tissue) grows or expands into the uterus. This tissue continues to act normally — thickening, breaking down and bleeding — during each menstrual cycle.

Prevalence 5% - 70%

Leiomyoma 

Leiomyomas or uterine fibroids are benign (not cancer) growths that develop from the muscle tissue of the uterus. They also are called myomas.

Prevalence 70%

Malignancy or hyperplasia 

Cancerous growth in the inner lining of the uterus; endometrial cancer (prevalence 15%), or the muscle wall; uterine sarcomas (rare prevalence), premalignant polyps.

Prevalence 3.5%

Coagulopathy 

A condition in which the blood's ability to coagulate (form clots) is impaired. It is also called a bleeding disorder.

Prevalence 13%

Endometrium 

Endometrial dysfunction is considered when no other causes are identified. Could be changes in endometrial hormones that result in impaired blood vessel constriction, accelerated breakdown of clots infection or inflammation.

Ovarian dysfunction 

Changes in normal functioning of ovaries resulting in hormonal imbalance (poly cystic ovarian syndrome, hypothyroidism, stress, obesity, anorexia, weight loss, extreme exercise).

Iatrogenic 

Medication related causes such as use of Intrauterine devices, hormonal steroid drugs and blood thinners.

Not otherwise classified 

Caesarean scar defect, chronic inflammation of endometrium.