Uterine fibroids (UFs) and urinary incontinence (UI) are two of the most common conditions affecting women, particularly during their reproductive and menopausal years. While fibroids are often associated with heavy bleeding and pelvic pain, these non-cancerous growths can also significantly impact urinary function. This article explores the established connection, detailing the physical mechanisms and identifying the specific types of incontinence that may arise from the presence of uterine fibroids.
Defining Uterine Fibroids and Urinary Incontinence
Uterine fibroids (leiomyomas or myomas) are non-cancerous growths that develop from the muscle tissue of the uterus. They vary widely in size, and their effects depend heavily on their location within the uterine structure. Fibroids are generally categorized by their location: intramural fibroids grow within the muscular wall, submucosal fibroids bulge into the uterine cavity, and subserosal fibroids develop on the outside surface of the uterus.
Urinary incontinence (UI) is defined as the involuntary leakage of urine, a condition that can negatively affect a person’s quality of life. This loss of bladder control happens when the complex system of nerves, muscles, and organs responsible for storing and releasing urine is disrupted. UI is a common problem, often becoming more prevalent as women age, but it is not a normal part of aging.
The Physical Mechanism Linking Fibroids to Bladder Issues
The primary reason uterine fibroids lead to urinary symptoms is the direct mechanical compression they exert on nearby pelvic organs. The uterus sits immediately behind the bladder, and as fibroids grow, they enlarge the uterus and push against the bladder, reducing its functional capacity. This physical pressure is the core explanation for why fibroids are linked to urinary difficulties.
Fibroids growing on the outer surface (subserosal) or large intramural fibroids are the most likely to press on the bladder. This external pressure physically restricts the bladder, meaning it holds less urine before the urge to void occurs. Resulting symptoms frequently include the need to urinate more than eight times a day and having to wake up multiple times at night, a condition known as nocturia.
The mass can also affect the urethra, the tube that carries urine out of the body. Pressure on the urethra or pelvic floor structures can interfere with the muscles that control urine flow. Furthermore, the continuous bulk of a large fibroid can sometimes contribute to or exacerbate general weakness in the pelvic floor.
Recognizing the Specific Types of Incontinence
The mechanical pressure from fibroids most commonly manifests as two specific patterns of urinary incontinence: stress and urgency-related symptoms. Stress Urinary Incontinence (SUI) is the involuntary loss of urine during activities that increase abdominal pressure, such as coughing, sneezing, or lifting heavy objects. While SUI is often linked to weakened pelvic floor muscles, a large fibroid near the front of the uterus can mimic or worsen this condition by transmitting pressure directly onto the bladder neck and urethra.
Urge Incontinence, or overactive bladder symptoms, results from an intensified need to urinate. The fibroid’s pressure irritates the bladder wall, signaling fullness prematurely and leading to a sudden, intense urge to pass urine. Women with fibroids may experience a combination of both stress and urge symptoms, a condition termed mixed incontinence.
The presence of a large fibroid can also lead to incomplete bladder emptying, which may progress to overflow incontinence. In this less common scenario, the fibroid physically obstructs the outflow of urine, causing the bladder to become over-distended and leak small amounts constantly. Identifying the specific pattern of leakage helps determine if the incontinence is purely a pressure effect from the fibroid mass.
Treatment Pathways for Fibroid-Related Incontinence
The most effective treatment for incontinence caused by uterine fibroids is addressing the underlying mass creating the pressure. Resolving the fibroid often leads to a reduction or complete elimination of urinary symptoms. Diagnostic testing is the first step, involving a pelvic exam, ultrasound, or Magnetic Resonance Imaging (MRI) to map the size and precise location of the fibroids in relation to the bladder.
Treatment options focus on either reducing the fibroid size or surgically removing the growth. Minimally invasive procedures like Uterine Fibroid Embolization (UFE) block the blood supply to the fibroid, causing it to shrink and relieving pressure on the bladder. Surgical options include a myomectomy, which selectively removes the fibroids while preserving the uterus, or a hysterectomy, which is a definitive solution for both the fibroids and the related symptoms.
While definitive treatment targets the fibroid, non-surgical management can provide temporary relief. Pelvic floor muscle exercises, such as Kegels, help strengthen the muscles that control urination, potentially mitigating leakage, especially SUI. Additionally, lifestyle adjustments, such as managing fluid intake, avoiding bladder irritants like caffeine, and addressing chronic constipation, can help reduce the frequency and severity of urinary symptoms until the fibroid is treated.