Most common causes of abnormal uterine bleeding

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Most common causes of abnormal uterine bleeding


Abdominal pain

Abnormal uterine bleeding is one of the most common reasons for patients to visit the gynaecologist. At different ages, different factors may be responsible for uterine bleeding. In younger patients, it is mainly hormonal disorders or polyps, while in older women, tumours of the reproductive tract must necessarily be taken into account. It should be remembered that bleeding may also be caused by systemic problems outside the gynaecology, such as blood clotting disorders.


What is abnormal uterine bleeding?

Abnormal uterine bleeding is also often abbreviated AUB (abnormal uterine bleeding) and includes a group of menstrual disorders in the form of inappropriate frequency or volume. Physiologically, menstruation should occur every 28+/-5 days and the amount of blood lost in menstruation should be approximately 50 ml.

Abnormal uterine bleeding can be classified as:

  • Hypermenorrhea - menstrual periods that are too heavy (more than 100 ml)
  • Hypomenorrhea - periods that are too scanty (less than 30 ml)
  • Dysmenorrhea - severe perimenstrual pain
  • Menorrhagia - very heavy, haemorrhagic periods
  • Metrorrhagia - bleeding outside the menstrual period
  • Menometrorrhagia - heavy bleeding outside the menstrual period

Uterine bleeding can be chronic, if the disorder has lasted for most of the last 6 months, or acute - a sudden episode of heavy bleeding.

Endocrine disorders - the most common cause of bleeding in young women

The course of the menstrual cycle is entirely hormonally determined. Any disturbance in the functioning of the hypothalamus, pituitary or ovary can cause significant changes in hormone levels and disturbances in the menstrual cycle, also in the form of abnormal uterine bleeding, mainly intermenstrual bleeding. Hormonal imbalance with a predominance of oestrogens leads to a thickening of the endometrial layer (endometrium) and its exfoliation in the form of bleeding.

It is worth noting here that scanty bleeding occurs in about 15% of perovulatory women due to rupture of the vascularised Graaf follicle, from where the egg is released. This is a physiological phenomenon that should not be confused with abnormal uterine bleeding.

photo: panthermedia

Uterine polyps as a cause of uterine bleeding

Uterine polyps are localised glandular proliferations of the endometrium located in the uterine cavity (endometrial polyp) or its cervix (cervical polyp). The lesions are spherical in shape, varying in size from a few millimetres to a few centimetres, and can be either uveal ('sagging') or non-uveal. High levels of the sex hormone oestrogen in particular contribute to their formation, but also civilisation diseases such as hypertension and diabetes.

Due to the large blood supply, the lesions, especially those of a larger size, are the cause of abnormal uterine bleeding - intermenstrual or at the time of menstruation with excessive abundance. Polyps located in the cervix also tend to bleed after intercourse as a result of breaching their surface.

Nowadays, the primary treatment for polyps is their excision with a special electric loop or scissors during a hysteroscopy procedure, which involves inserting a camera into the uterine cavity through the vagina and cervix. In selected cases, treatment can be started with hormonal therapy, which can cause the polyp to flake off along with the endometrium, e.g. during menstruation.