Fibroids are non-cancerous growths that develop in the muscular wall of the womb (uterus).

These growths are made up of muscle and tissue and can be different sizes. Some can be the size of a pea, others can be the size of a melon. They're sometimes known as uterine myomas or leiomyomas.

Fibroids are common. Around 1 in 3 people who menstruate develop them at some point in their life. They’re more common as you get older.


Many people don't know that they have fibroids because they don't have any symptoms. This is nothing to worry about.

Non-urgent advice: Speak to your doctor if:

You're worried about your symptoms or you regularly have:

  • heavy periods
  • painful periods
  • tummy (abdominal) pain
  • lower back pain
  • a frequent need to urinate
  • constipation
  • pain or discomfort during sex
  • symptoms which are affecting your day to day life

If your doctor thinks you might have fibroids, they'll usually refer you for an ultrasound scan to confirm the diagnosis.

Why fibroids develop

The exact cause of fibroids is unknown. They’re linked to the hormones produced by the ovaries, oestrogen and progesterone. Fibroids usually develop and grow as long as the ovaries are producing these hormones. Fibroids may continue to grow during pregnancy. They tend to shrink when these hormone levels fall, such as after the menopause.

Types of fibroids

There are different types of fibroid. The main types of fibroids are:

  • intramural – the most common type of fibroid, these develop in the muscular wall of the womb
  • subserosal – fibroids that develop on the outside part of the wall of the womb and can become very large
  • submucosal – fibroids that develop in the muscular layer of the womb beneath the womb's inner lining (endometrium) and grow into the inside of the womb
  • pedunculated – subserosal or submucosal fibroids that are attached to the womb with a narrow stalk of tissue


Fibroids will often shrink after the menopause, as hormone levels in your body change.

If you have fibroids, but you're not affected by any symptoms then you don't need treatment.

However, if you do have symptoms, your doctor can recommend the right treatment for you. Treatment options include:

  • over-the-counter pain relief like ibuprofen
  • the contraceptive pill which can reduce heavy menstrual bleeding
  • medication taken only during your period that can reduce heavy menstrual bleeding
  • medicines that can shrink fibroids by lowering your oestrogen and progesterone levels
  • in rare cases, surgery

Your doctor will discuss these treatments with you and you can ask any questions that you might have.

Fibroids and getting pregnant

If you're having difficulty getting pregnant, your doctor or specialist may suggest extra support or treatments that can help. Your doctor will discuss these with you and you can ask any questions that you might have.

Last updated:
28 February 2023

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