Fibroids

What are fibroids?

Fibroids are noncancerous growths found in the muscle wall of the uterus. They can vary in size from a pea to a rockmelon or bigger.

Fibroids can grow on the outer wall of the muscle (subserosal), within the muscle wall (intramural), on the inner wall lining the cavity of the uterus (submucosal), or a combination of these.

Up to 70% of women aged under 50 have fibroids. After menopause, fibroids usually shrink and may even disappear.

Symptoms of fibroids

If you have fibroids, you may not have any symptoms. But 20% to 30% of women experience symptoms such as:

• heavy periods or longer periods than normal
• painful periods
• bleeding in between periods – this depends on the size and position of the fibroids
• iron deficiency (anaemia), due to heavy periods, which can make you feel tired or dizzy.

Other symptoms may include:

• painful sex (dyspareunia)
• feeling heaviness or pressure in your back, bowel or bladder
• feeling like you haven’t emptied your bowel or bladder
• weeing a lot
• swelling in your lower abdomen.

Causes of fibroids

We don’t know exactly what causes fibroids, but we do know the female hormones oestrogen and progesterone stimulate the growth of fibroids.

Some factors may increase the risk of developing fibroids, for example:

• a family history of fibroids
• starting your periods early
• polycystic ovary syndrome (PCOS)
• obesity
• high blood pressure.

How are fibroids diagnosed?

Fibroids can be diagnosed in different ways, for example:

• an external ultrasound on your belly (abdomen)
• an internal ultrasound via the vagina
• a magnetic resonance imaging (MRI) scan
• a hysteroscopy – a thin telescope shows the inside of your uterus
• a laparoscopy – a thin telescope goes into your belly button to see your pelvic organs (performed under general anaesthetic).

I saw we’ve previously used “pelvic ultrasound” or are you wanting to emphasize it’s an internal procedure. Later in the topic we say “an internal ultrasound via the vagina” - is that better?

How do fibroids affect fertility?

Fibroids can cause fertility problems, depending on the size and location of the fibroids. They can also cause pregnancy complications. Ask your doctor for more information.

Treatments for fibroids

Most fibroids don’t need treatment, unless you’re planning to get pregnant or your symptoms stop you from doing daily activities.

If fibroids don’t affect your daily life, you can choose to leave them untreated.

Medicines for fibroids

Your doctor may recommend different medicines to treat your fibroids. For example, mefenamic acid tablets, tranexamic acid tablets or hormone medicines such as the Pill or an IUD.

Your doctor may recommend a combination of medicines to shrink your fibroids, usually when fertility is an issue.

Ask your doctor about the benefits and risks of each medicine.

Note that after you stop treatment, your fibroids can grow back.

Radiological treatment for fibroids

You may be able to treat your fibroids with radiological treatment. For example:

• a non-surgical procedure called ‘uterine artery embolisation’ that blocks blood supply to part of the uterus
• ultrasound guided by MRI – only suitable for certain types of fibroids.

Surgery for fibroids

You may need surgery to remove your fibroids. The type of surgery will depend on the size and position of your fibroids. Ask your doctor or specialist for more information.

When to see your doctor about fibroids

See your doctor if you experience symptoms such as:

• a sudden change to your bleeding
• very heavy periods (i.e. soaked pads every hour or golf-ball sized blood clots)
• unexplained weight loss or loss of appetite.

Related resources

Download our fibroids fact sheet (PDF 200KB)