What Are Uterine Fibroids? A Simple Guide for Patients

Uterine fibroids (also known as leiomyomas or myomas) are benign (non-cancerous) growths that develop from the muscle tissue of the uterus. They are the most common type of tumour in women of reproductive age. While sometimes single, they often appear in groups and can vary dramatically in size, from as small as a pea to as large as a melon.

Fibroids are not cancerous and do not increase your risk of developing uterine cancer. They are classified by their location within the uterus:

• Subserosal: Growing on the outside of the uterus (can cause bulk/pressure symptoms).
• Intramural: Growing within the muscular wall of the uterus (the most common type; can cause heavy bleeding and pain).
• Submucosal: Growing just underneath the inner lining of the uterus (the rarest type, but the most likely to cause heavy bleeding and fertility problems).

Who Does It Affect & How Common Are They?

Uterine fibroids are exceptionally common and by the age of 50, up to 75%-80% of women will have developed fibroids. They most frequently affect women during their reproductive years, typically in their 30s, 40s, and 50s. They are particularly common among women of Black ethnicity, who tend to develop them at a younger age, have larger and more numerous fibroids, and experience more severe symptoms.

Risk Factors & Important New Discoveries

• Age & Hormones: Fibroids are oestrogen and progesterone-sensitive, meaning they grow in response to your natural hormones. This explains why they are rare before puberty, can grow during pregnancy, and typically shrink naturally after the menopause.
• Family History: Having a close relative (mother, sister) with fibroids significantly increases your own risk.
• Early Menarche: Starting your periods at a young age.
• Childbirth: Risk increases with age and the number of full-term pregnancies you have had.
• Diet: A diet high in red meat and low in green vegetables has been linked to a higher risk.

Two critical scientific breakthroughs in 2025 have changed our understanding of fibroids:

1. A Link to Heart Disease: A large study of over 2.7 million women, published in December 2025, found that long-term heart disease risk in women diagnosed with uterine fibroids was more than 80% higher compared to women without fibroids. The elevated risk persisted across all races and ages but was particularly strong in women under 40. This means that a diagnosis of fibroids may now be considered an important marker for a woman’s overall cardiovascular health.
2. The Role of Vitamin D: Multiple 2025 studies have reinforced the strong link between vitamin D deficiency and fibroid development. Low-dose vitamin D supplementation has been shown to effectively reduce fibroid size in women with a deficiency within 6 months.

Common Symptoms: Listen to Your Body

• Heavy Menstrual Bleeding (Menorrhagia): This is the most frequent symptom, with prolonged, very heavy periods often containing large blood clots. This can lead to iron-deficiency anaemia, causing fatigue, weakness, and breathlessness.
• Pelvic Pressure & Pain: A sense of fullness, bloating, or pressure in the lower abdomen. Some women experience dull, aching pelvic pain or lower back pain.
• Bladder: Frequent urination, a sudden urgent need to pass urine (urinary urgency), or difficulty fully emptying the bladder.
• Bowel: Constipation, rectal pressure, or a feeling of incomplete bowel evacuation.
• Painful Periods (Dysmenorrhea): Severe period cramps are a common complaint.
• Pain During or After Sex (Dyspareunia): Particularly with certain types of fibroids.
• Enlarged Uterus: In some cases, the uterus can become significantly enlarged, appearing similar to a pregnancy.

How Is It Diagnosed? A Step-by-Step Guide

• Pelvic Examination: Your gynaecologist may feel an enlarged, irregularly shaped, or firm uterus during a routine bimanual pelvic exam.
• Ultrasound (First-Line Imaging): A transvaginal ultrasound (a small probe placed in the vagina) combined with a transabdominal scan is the initial, first-line imaging test of choice.
• Saline Infusion Sonohysterography (SIS): If a submucosal fibroid is suspected (the type that distorts the uterine cavity and causes heavy bleeding), a small amount of sterile fluid may be instilled into the uterus during the ultrasound to get a clearer view of the cavity lining.
• Magnetic Resonance Imaging (MRI): An MRI is a more detailed scan and is now the recommended second-line test for complex cases or when detailed surgical planning is required.
• Hysteroscopy: This allows a direct look at the cavity and is used both to diagnose and treat submucosal fibroids in the same procedure.

Management & Treatment Options

Medical Management (To Control Symptoms)

This is often the first-line approach, especially for heavy bleeding, and can be highly effective.

• Tranexamic Acid: A non-hormonal tablet taken only during your period to reduce heavy bleeding by up to 50%.
• Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): Medicines like ibuprofen or naproxen can help reduce pain and lighten bleeding.
• Levonorgestrel-Releasing Intrauterine System (LNG-IUS, e.g., Mirena): This hormonal coil works by thinning the uterine lining.
• Combined Oral Contraceptive Pill: The Pill can help regulate and lighten periods and reduce pain.

New & Advanced Medical Therapies

• Oral GnRH Antagonists (e.g., Relugolix, Linzagolix): These are once-daily pills that work by reducing oestrogen levels, rapidly stopping heavy bleeding and shrinking fibroids.
• GnRH Agonists (e.g., Leuprolide): They are now primarily used for short-term preoperativemanagement (typically 3-6 months) to shrink fibroids and correct anaemia before surgery.

Interventional & Minimally Invasive Procedures

• Uterine Artery Embolisation (UAE): A radiologist blocks the blood vessels supplying the fibroids, causing them to shrink. UAE is a safe and effective procedure.
• Radiofrequency Ablation (RFA): A minimally invasive technique using heat energy to destroy (ablate) fibroid tissue.
• Microwave Ablation (MWA): A newer thermal ablation technique is an effective, minimally invasive option.
• MRI-Guided High-Intensity Focused Ultrasound (MRgFUS/HIFU): A completely non-invasive, outpatient procedure.

Surgical Options

• Myomectomy (Fibroid Removal): This is the gold standard surgical option for women who wish to preserve their fertility or keep their uterus. The myomectomy can be performed either as open procedure or laparoscopically depending upon the number, size and location of fibroids.
• Hysterectomy (Uterus Removal): This is the only definitive cure for fibroids, as the uterus is removed entirely.

Frequently Asked Questions (FAQs)

Q: Are uterine fibroids cancerous?
A: No. Fibroids are almost always benign (non-cancerous). They do not increase your risk of developing uterine cancer.

Q: Can fibroids affect my ability to get pregnant?
A: They can, especially submucosal fibroids which can distort the uterine cavity and interfere with embryo implantation. However, many women with fibroids conceive naturally and have healthy pregnancies.

Q: What happens if I choose to do nothing about my fibroids?
A: For asymptomatic fibroids, this is an excellent choice. We simply monitor them with regular pelvic exams or periodic ultrasounds to ensure they are not changing.

Q: What is the best treatment for fibroids?
A: There is no single “best” treatment. The right option depends entirely on you: your symptoms, the characteristics of your fibroids, your age, and your personal desire for future pregnancy.

Q: Can lifestyle changes help manage fibroids?
A: Maintaining a healthy weight, eating a diet rich in fruit and vegetables, and ensuring you have adequate vitamin D levels (through safe sun exposure or supplementation) are all sensible, low-risk measures that may help reduce your risk or slow growth.

eGynaecologist Advice

• If you are experiencing very heavy, prolonged, or painful periods, pelvic pressure, or any of the other symptoms, you should seek a gynaecological consultation.
• If you have been told about the diagnosis of fibroids, you should consider monitoring your fibroids with annual ultrasound scan to check on rate of their growth and their impact on your personal health.