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About Fibroids


What are fibroids?

Uterine fibroids, medical name leiomyoma (leio = smooth muscle, myoma = a tumour formed of muscular tissue) are benign (non-cancerous) tumours of the uterus or womb. They are the commonest tumours found in the human body. It is estimated that approximately 20-70% of women have fibroids. Many women never know they have them, as in 75% of women they do not cause symptoms.

Symptoms seem to appear in a woman's 30s or 40s. Most treatments for fibroids are carried out on women who are in their early to mid 40s, although the ages range from 30s to 60s. A few younger women develop symptoms from fibroids. Symptoms will tend to subside after menopause, as the reduction in hormone levels reduces blood flow to the fibroids and they shrink.

There is a higher incidence in Afro-Caribbean women and those who don't have children. There is also thought to be a genetic connection, as fibroids sometimes run in families. Fibroids are also commoner in obese women.

Fibroids can get very large, as big as watermelons. The number can vary from one to many.

Fibroids can occur elsewhere in the body, but the uterus (womb) is the commonest site.


What causes fibroids?

The exact cause of fibroids is not known. There is thought to be a link between oestrogen and fibroids. Women who have not had children are more likely to suffer from fibroids, while being on the contraceptive pill and smoking seems to give a lower incidence.


Embolisation procedureTypes of fibroid

Fibroids can be classified according to their position in the uterus or womb:

  • Subserosal - towards the outside of the womb / uterus
  • Intramural - in the wall of the womb / uterus
  • Submucosal - towards the middle of the womb / uterus

They can also be pedunculated - on a stalk, or non-pedunculated. Women can have a mixture of types of fibroid.


These occur outside the wall in the outermost layer (serosa) of the uterus (womb). They can cause compression on the surrounding tissues, such as the bladder and bowel.


These grow within the wall of the uterus and can cause pressure on the bladder and / or uterus and infertility or miscarriage.


As the name suggests these occur just below the lining (mucosa) of the uterus (womb) and are associated with menorrhagia - heavy bleeding



Approximately 25% of women with fibroids have symptoms. These vary with the position, type of fibroid and size. Common symptoms are: -

  • Menorrhagia - heavy or prolonged periods
  • Anaemia - from prolonged heaving bleeding
  • Dysmenorrhea - painful periods
  • Bladder incontinence/urgency - difficulty or need to urinate / pee frequently
  • Infertility or miscarriage
  • Pressure symptoms on the bowel leading to constipation
  • Pressure symptoms on the ureters (tubes leading from each kidney to the bladder) and / or bladder and / or kidney
  • Back pain and sciatica (pain in the lower back and down the leg)
  • Abdominal swelling as in pregnancy
  • Indigestion, discomfort sitting etc as in pregnancy
  • Painful intercourse and dryness in the vagina

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