Uterine fibroids, also known as leiomyomas, are non-cancerous growths that develop within the muscular wall of the uterus. These growths are common, affecting a large percentage of women. While many women with fibroids experience heavy bleeding or pelvic pain, a frequent complaint is a persistent problem with urination. Fibroids often exert mechanical pressure on the nearby bladder, which significantly alters normal urinary function. This physical interaction between the growing uterus and the urinary system is the source of many daily symptoms.
The Mechanism of Bladder Compression
The uterus and the bladder are close neighbors within the pelvic cavity. As a fibroid grows, especially those that develop on the outer surface of the uterus (subserosal fibroids), the uterus expands. If this expansion occurs toward the front of the body, the mass directly pushes against the bladder wall.
This physical impingement restricts the bladder’s ability to stretch and fill to its normal capacity. The bladder is a muscular organ designed to hold urine until it reaches a certain volume. However, the constant pressure from the fibroid acts as a physical limitation, causing the bladder to signal the need to empty much sooner, even when it only contains a small amount of urine.
Specific Urinary Symptoms Caused by Fibroids
The physical compression of the bladder leads directly to a distinct set of lower urinary tract symptoms. These symptoms vary in severity but often include:
- Urinary frequency: Needing to urinate much more often than normal.
- Urinary urgency: The sudden, intense sensation that one must urinate immediately.
- Nocturia: Waking up multiple times during the night to empty the bladder, disrupting sleep.
- Incomplete voiding: Difficulty fully emptying the bladder, which can lead to urinary retention.
- Stress incontinence: Mild leakage of urine during activities like coughing or sneezing, caused by pressure weakening the pelvic floor muscles.
Diagnostic Steps and Ruling Out Other Causes
A doctor must confirm that the fibroids are the actual cause of the urinary issues and not another common condition. The diagnostic process starts with a thorough pelvic examination, where the physician may feel an enlarged or irregularly shaped uterus. This physical finding suggests the presence of a mass that could be impacting nearby organs.
Imaging is then used to visualize the pelvic organs and precisely map the fibroids. Transvaginal or abdominal ultrasound is commonly used to confirm the presence, size, and location of the fibroids relative to the bladder. In some cases, a Magnetic Resonance Imaging (MRI) scan provides more detailed information on the exact relationship between the fibroid and the urinary tract structures. Doctors must also perform a differential diagnosis, ruling out other conditions that cause similar symptoms, such as urinary tract infections (UTIs), diabetes, or an unrelated overactive bladder syndrome. A post-void residual test measures the amount of urine left in the bladder after a person attempts to empty it, helping quantify incomplete voiding caused by the fibroid pressure.
Treatment Options Focused on Symptom Relief
Treatment aims to reduce the size of the fibroid or remove the mass entirely to relieve external pressure on the bladder. Initial approaches involve hormonal medications, such as gonadotropin-releasing hormone (GnRH) agonists. These medications temporarily shrink fibroids by reducing estrogen levels and are used for rapid symptom relief or to reduce fibroid size before a planned procedure.
A less invasive option is Uterine Fibroid Embolization (UFE), performed by an interventional radiologist. UFE involves injecting tiny particles into the arteries supplying the fibroids, blocking blood flow and causing the growths to shrink significantly. This reduction in mass often leads to improvement in bladder pressure symptoms.
Surgical interventions offer definitive solutions, with the choice depending on the patient’s future reproductive plans. A myomectomy surgically removes the fibroids while preserving the uterus. For women who have completed childbearing or have severe symptoms, a hysterectomy—the complete removal of the uterus—eliminates the source of the fibroids permanently. All treatments share the goal of restoring the bladder’s functional capacity and relieving urinary symptoms.