Why Fibroids Can Cause Heavy Bleeding

Heavy menstrual bleeding is the most common symptom of uterine fibroids and one of the main reasons women seek gynecologic care. Studies estimate that 30–50% of women with fibroids experience heavy or prolonged menstrual bleeding, often severe enough to interfere with daily life, work productivity, and overall well-being. Fibroids are also a leading cause of iron-deficiency anemia in women of reproductive age.

Uterine fibroids themselves are extremely common. By age 50, 70–80% of women will develop fibroids, although many remain asymptomatic. When symptoms do occur, heavy bleeding is the most frequent and most disruptive. Understanding why fibroids cause excessive bleeding helps women recognize when their symptoms are not normal and why treatment can make a dramatic difference.

1. Fibroids Increase the Surface Area of the Uterine Lining

Fibroids, especially submucosal fibroids, which grow just beneath the uterine lining, expand and distort the endometrium. During menstruation, a larger surface area of lining must shed, which directly increases menstrual blood loss.

Clinical studies show that even small submucosal fibroids are associated with significantly higher menstrual blood volume compared to women without fibroids, making location more important than size alone.

2. Fibroids Disrupt Normal Uterine Contractions

During a normal period, the uterus contracts rhythmically to compress blood vessels and limit bleeding. Fibroids interfere with this process by:

• Altering uterine shape
• Disrupting coordinated muscle contractions

When these contractions are impaired, blood vessels remain open longer, resulting in prolonged or “flooding” bleeding, large clots, and periods that last more than seven days.

3. Abnormal Blood Vessel Formation

Fibroids are associated with abnormal angiogenesis, meaning the blood vessels in and around fibroids are structurally different from normal uterine vessels. These vessels tend to be:

• Fragile
• Disorganized
• Less responsive to hormonal signals that normally stop bleeding

This abnormal vascular pattern contributes to heavy, unpredictable menstrual flow.

4. Hormonal Sensitivity Amplifies Bleeding

Fibroids are highly responsive to estrogen and progesterone, the hormones that regulate the menstrual cycle. These hormones promote:

• Fibroid growth
• Thickening of the uterine lining

As a result, menstrual bleeding often worsens during reproductive years and improves after menopause, when hormone levels decline.

5. Heavy Bleeding Can Lead to Anemia

Chronic heavy bleeding from fibroids is one of the leading causes of iron-deficiency anemia, affecting up to 60% of women with symptomatic fibroids. Anemia may cause fatigue, dizziness, shortness of breath, headaches, and difficulty concentrating—symptoms that are frequently overlooked or attributed to stress.

Take the Next Step Toward Relief

Heavy menstrual bleeding is not something you have to live with, especially when fibroids are the underlying cause. Effective evaluation and personalized treatment can significantly reduce bleeding, restore energy, and improve quality of life. If you are experiencing heavy or prolonged periods, anemia, or symptoms affecting your daily activities, a comprehensive gynecologic evaluation is an important first step.

Dr. Marinescu specializes in the diagnosis and management of uterine fibroids, including advanced medical and minimally invasive surgical options tailored to each patient’s goals and stage of life. To schedule a consultation, contact OBGYN-CARE and take the next step toward expert care and lasting relief.