Uterine Fibroids: What They Are, Why They Grow & How to Support Your Body

What Are Fibroids?

Uterine fibroids — also called leiomyomas or myomas — are non-cancerous growths that develop in or on the muscular wall of the uterus. They are composed of smooth muscle cells and fibrous connective tissue, and they can range dramatically in size: from as small as a seedling to, in rare cases, large enough to distort the shape of the uterus entirely. They almost always occur in multiples rather than as a single growth.

Despite being so extraordinarily common — affecting an estimated 70–80% of women by age 50, with Black women developing them earlier, more frequently, and in greater numbers — fibroids remain widely misunderstood. Many women have fibroids without knowing it. Others are living with debilitating symptoms and have been told little more than "we can take a wait-and-see approach" or "you may eventually need a hysterectomy." Neither of those responses reflects the full picture of what's available to you.

Let's change that.

Types of Fibroids

Where a fibroid grows within or around the uterus significantly affects which symptoms you experience and how severely. There are four main types:

• Intramural fibroids grow within the muscular wall of the uterus and are the most common type. They can cause heavy bleeding, pelvic pressure, and an enlarged uterus.
• Submucosal fibroids develop just beneath the inner lining of the uterus and are the type most likely to cause heavy menstrual bleeding, prolonged periods, and fertility challenges.
• Subserosal fibroids grow on the outer surface of the uterus and can press on nearby organs including the bladder and bowel, causing urinary frequency, constipation, and lower back pain.
• Pedunculated fibroids are attached to the uterus by a stalk and can be either intracavitary or external. If the stalk twists, it can cause acute, severe pelvic pain.

Symptoms

The range of symptoms women experience with fibroids is wide, and it correlates strongly with the size, number, and location of the growths. Some women are completely asymptomatic and discover fibroids incidentally during a routine ultrasound. Others are managing a genuinely significant daily burden.

The most common symptoms include:

• Heavy menstrual bleeding, often with large clots
• Prolonged periods lasting seven days or more
• Pelvic pressure, heaviness, or a sensation of fullness in the lower abdomen
• Frequent urination or difficulty emptying the bladder fully
• Constipation or difficulty with bowel movements
• Lower back or leg pain
• Pain during sex
• Iron deficiency anaemia as a consequence of blood loss
• Complications with pregnancy or fertility in some cases

Heavy bleeding leading to anaemia is one of the most significant downstream consequences of fibroids — and anaemia itself causes fatigue, brain fog, poor exercise tolerance, and lowered mood, compounding an already difficult situation.

Why Fibroids Grow

The honest answer is that the scientific community does not yet have a complete picture of fibroid aetiology. What we do know is that fibroids are influenced by hormones — particularly oestrogen and progesterone — genetics, growth factors, and increasingly, environmental exposures. They rarely develop before puberty and typically shrink after menopause when oestrogen levels decline substantially, which tells us that reproductive hormones play a meaningful role.

Research also points to epigenetic factors: the way genes are expressed (or silenced) in uterine muscle cells appears to be altered in fibroid tissue, causing abnormal proliferation. Chronic inflammation and oxidative stress are also increasingly implicated in the initiation and progression of fibroid growth.

Certain risk factors are well-established. These include family history, early onset of menstruation, obesity, a diet high in red meat and low in fruits and vegetables, vitamin D deficiency, and — critically in terms of racial health equity — the physiological effects of chronic stress related to racial trauma and systemic racism, which may help explain why Black women in particular are so disproportionately affected.

The Estrogen-Fibroid Connection

Oestrogen is a potent growth stimulator for fibroid tissue. Fibroid cells have a higher concentration of oestrogen receptors than normal uterine muscle cells, making them especially responsive to circulating oestrogen. This is why states of oestrogen dominance — where oestrogen is high relative to progesterone — tend to drive fibroid growth.

Oestrogen dominance can arise from several overlapping sources: impaired liver detoxification of oestrogen metabolites, poor gut health (specifically a dysbiotic gut microbiome that recirculates oestrogen rather than excreting it), excess body fat (which is itself oestrogen-producing), chronic stress suppressing progesterone production, and xenoestrogen exposure from plastics, personal care products, and pesticides.

Progesterone is more nuanced — it was long thought to be purely protective against fibroid growth, but research now suggests it can also stimulate fibroid cells in certain contexts. What appears to matter most is the ratio between the two hormones and the overall hormonal milieu rather than oestrogen in isolation.

Supporting Your Body

While fibroids cannot always be dissolved through lifestyle alone — particularly larger ones — there is meaningful evidence that reducing the hormonal and inflammatory drivers of fibroid growth can slow their progression and meaningfully reduce symptoms. Here is where to focus:

• Support oestrogen metabolism through the liver: eat cruciferous vegetables daily (broccoli, cauliflower, kale, Brussels sprouts), ensure adequate B vitamins and magnesium, and minimise alcohol, which significantly impairs oestrogen clearance
• Cultivate a healthy gut microbiome by eating a diverse range of fibre-rich plant foods and, if needed, supporting with targeted probiotics to reduce beta-glucuronidase activity — the enzyme that recirculates oestrogen in the gut
• Reduce xenoestrogen exposure by choosing glass or stainless steel over plastic where possible, opting for organic produce especially for the Environmental Working Group's "Dirty Dozen," and switching personal care and cleaning products to lower-toxin alternatives
• Address vitamin D deficiency — studies show women with fibroids are more likely to be deficient, and vitamin D has demonstrated anti-proliferative effects on fibroid tissue in research
• Eat an anti-inflammatory diet rich in oily fish, colourful vegetables, nuts, and seeds, while reducing ultra-processed foods, seed oils, and refined sugar
• Maintain a healthy body weight, since adipose tissue produces oestrogen and excess weight amplifies the oestrogen-fibroid cycle
• Consider targeted supplementation: green tea extract (EGCG), which has shown promise in reducing fibroid volume in clinical trials, as well as systemic enzymes like nattokinase and serrapeptase, which may support fibroid remodelling

When to Consider Medical Treatment

Not all fibroids require intervention, and watchful waiting is entirely appropriate for small, asymptomatic fibroids. But when symptoms are significantly affecting your quality of life — heavy bleeding causing anaemia, severe pain, bladder or bowel disruption, or fertility challenges — there is a range of medical and procedural options worth knowing about.

These range from hormonal medications (like GnRH agonists or the newer GnRH antagonists) that temporarily shrink fibroids, to minimally invasive procedures like uterine fibroid embolisation (UFE) and focused ultrasound (MRI-guided or high-intensity), to myomectomy (surgical removal of fibroids while preserving the uterus), to hysterectomy as a definitive last resort. Each option has different implications for future fertility, recovery time, and recurrence risk.

I always encourage women to seek out a specialist who will present the full menu of options — not just the most expedient surgical route. You deserve informed choice and enough time to ask questions. Your uterus, your decision.

This article is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider for diagnosis and treatment of any health condition.