Uterine fibroids are noncancerous growths that develop in or on the muscular walls of the uterus. Many women have uterine fibroids sometime during their lives but have no symptoms. In other cases, fibroids can cause symptoms like heavy menstrual bleeding, pelvic pressure or pain, and problems with pregnancy and fertility. A common question many women have is whether fibroids can press on other organs in the pelvis and cause symptoms.
What are uterine fibroids?
Uterine fibroids, also known as leiomyomas or myomas, are benign smooth muscle tumors that grow in the wall of the uterus (womb). They are extremely common, with estimates that 70-80% of women will develop fibroids by age 50. However, the majority of fibroids do not cause any symptoms. When fibroids do cause symptoms, they may include:
- Heavy, prolonged menstrual periods
- Pelvic pain and pressure
- Frequent urination
- Pain during sexual intercourse
- Lower back pain
- Reproductive problems, like infertility, multiple miscarriages, and early labor
Fibroids range greatly in size, from microscopic to several inches across. They also vary in location within the uterus, with some growing just under the lining (submucosal), some in the muscle wall (intramural), and some on the exterior surface (subserosal). Generally, submucosal fibroids are more likely to cause symptoms than intramural or subserosal fibroids.
Can fibroids press on the bladder?
Yes, fibroids can sometimes press on the bladder, leading to bladder-related symptoms. The bladder sits in front of the uterus within the pelvis. So a fibroid growing on the front wall of the uterus may start to press against the bladder as it enlarges.
Signs that a fibroid may be pressing on the bladder include:
- Frequent urination
- Urgency to urinate
- Waking up multiple times at night to urinate
- Incomplete bladder emptying
- Incontinence
These symptoms occur because the fibroid is compressing the bladder, reducing its capacity and irritating the bladder wall. A very large fibroid could even block the ureters, leading to kidney damage if left untreated.
Diagnosing bladder compression
If a woman with uterine fibroids experiences urinary symptoms, her doctor will typically perform tests to check for bladder compression. This may include:
- Pelvic exam
- Ultrasound
- MRI
- Urine tests
- Bladder scope exam (cystoscopy)
Finding that a fibroid is pressing on the bladder will help guide treatment recommendations.
Can fibroids press on the rectum?
Yes, uterine fibroids can sometimes grow large enough to put pressure on the rectum. The rectum is located behind the uterus, so posterior fibroids are most likely to impact rectal function.
Symptoms of rectal compression may include:
- Difficulty having bowel movements
- Straining and incomplete evacuation
- Constipation
- Narrowing of stools
- Rectal pain or pressure
These occur when the fibroid pushes against the rectum, obstructing the passageway and disrupting normal bowel movements. Very large fibroids could potentially prolapse through the rectum, requiring immediate emergency treatment.
Diagnosing rectal compression
To check for rectal compression from fibroids, doctors can perform:
- Pelvic exam
- Abdominal palpation
- Transvaginal ultrasound
- MRI
- Anoscopy/sigmoidoscopy
Identifying rectal compression can help determine the best fibroid treatment options to relieve symptoms.
Can fibroids press on the ureters?
The ureters are the narrow tubes that carry urine from the kidneys to the bladder. In some cases, fibroids can grow large enough to press on one or both ureters. This is more common with very large fibroids.
Symptoms of ureter compression may include:
- Flank pain (in the side)
- Kidney pain
- Sudden severe pelvic pain
- Nausea, vomiting
- Fever and chills
- Decreased urine output
These occur when the fibroid pushes on and obstructs the ureter. This backs up urine in the kidney, leading to swelling and kidney damage if not relieved. Complete blockage is a medical emergency requiring rapid treatment.
Diagnosing ureter compression
Tests doctors can use to check for ureter compression from fibroids include:
- Kidney ultrasound
- CT scan
- MRI
- Intravenous pyelogram (IVP)
Prompt diagnosis is essential to preserve kidney function and prevent permanent damage.
Can fibroids press on the bowel?
The bowel or intestines can sometimes be compressed by enlarging uterine fibroids. This is more likely with very large fibroids growing in the posterior uterus.
Symptoms of bowel compression may include:
- Bloating
- Cramping
- Abdominal fullness and distention
- Nausea
- Vomiting
- Constipation
- Diarrhea
These occur when the fibroid partially blocks or slows the intestinal tract, disrupting normal bowel function. Complete obstruction of the intestines is a dangerous condition requiring emergency fibroid removal.
Diagnosing bowel compression
If bowel obstruction from a uterine fibroid is suspected, tests may include:
- Abdominal exam
- Abdominal x-ray
- CT scan
- Barium enema
Quickly identifying bowel compression is vital to prevent a bowel perforation and dangerous infection.
Can fibroids press on the nerves?
The nerves supplying the pelvis and legs can sometimes be compressed by large fibroids inside the pelvis. Two nerves in particular are at risk:
- Sciatic nerve – Runs from the lower back through the buttocks and down the legs. Supplies sensation and strength to the legs.
- Pudendal nerve – Runs from the lower spine to the external genitalia. Supplies sensation to the vulva, clitoris, perineum, and anus.
Symptoms of nerve compression may include:
- Pain in the buttocks or legs
- Numbness and tingling in the legs, feet, or genital area
- Muscle weakness in the legs
- Difficulty moving the leg or foot
- Decreased sensitivity in the vulva or perineum
These occur when the enlarging fibroid puts pressure on the nerves. This can damage nerve function over time if the compression is not relieved.
Diagnosing nerve compression
Nerve compression from fibroids may be detected by:
- Neurological exam
- Nerve conduction studies
- MRI
Identifying compressed nerves can help target treatment to prevent permanent nerve injury.
Can fibroids press on the pelvic veins?
The veins that drain blood from the pelvis and legs can also be compressed by large fibroids inside the pelvis. The main veins at risk are:
- Ovarian veins – Drain the ovaries and uterus
- Internal iliac veins – Drain the pelvic organs and muscles
- External iliac veins – Drain the legs
Symptoms of pelvic vein compression may include:
- Heavy, painful menstrual periods
- Pelvic pain
- Pelvic heaviness and pressure
- Lower back pain
- Leg swelling
- Leg pain
These occur when the fibroid presses on and obstructs the veins draining the pelvis and legs. Blood and fluid can back up, causing congestion, swelling, and pain.
Diagnosing pelvic vein compression
Tests to check for compressed pelvic veins may include:
- Ultrasound
- MRI
- Venography (x-ray with contrast dye)
Identifying pelvic venous obstruction can help guide fibroid treatment to reduce symptoms.
Can fibroids press on the pelvic arteries?
Less commonly, very large fibroids may compress major arteries within the pelvis. This includes the:
- Common iliac arteries – Branch off the aorta and supply the pelvis and legs
- Internal iliac arteries – Supply the pelvic organs and muscles
- External iliac arteries – Supply the legs
Symptoms of pelvic artery compression may include:
- Severe pelvic pain
- Numbness and tingling in the pelvis, buttocks or legs
- Leg pain with walking (claudication)
- Weakness and fatigue in the legs
- No pulse in the leg
- Blueish discoloration of the legs
These result when the fibroid presses on and obstructs blood flow through the artery. This can significantly reduce blood supply to the pelvis and legs.
Diagnosing pelvic artery compression
Artery compression may be detected using:
- Pelvic exam
- Ultrasound
- CT angiography
- MRI angiography
- Arteriography
Identifying arterial obstruction is important to help restore normal blood flow and prevent organ damage.
When do fibroids require treatment?
Many women with fibroids require no treatment at all if they have minimal symptoms. However, treatment may be recommended if fibroids are:
- Causing significant heavy bleeding or anemia
- Causing pain, pressure, urinary problems, constipation
- Growing rapidly
- Affecting fertility and pregnancy
- Pressing on other pelvic organs
- Very large (e.g. >golf ball size)
The specific treatment depends on the woman’s age, severity of symptoms, desire for future fertility, and other factors. Options may include:
- Medications like birth control pills, GnRH agonists
- Uterine fibroid embolization (blocks blood flow to shrink)
- MRI-guided focused ultrasound fibroid ablation
- Myomectomy (surgical fibroid removal)
- Hysterectomy (surgical uterus removal)
Early treatment for rapidly growing or symptomatic fibroids can help avoid complications from compression of other organs.
Summary
In summary, uterine fibroids can sometimes grow large enough to put pressure on or compress surrounding pelvic organs, leading to troubling urinary, bowel, pain, and other symptoms. Commonly compressed structures include the bladder, rectum, ureters, nerves, blood vessels, and intestines. Large fibroids causing severe symptoms or compressing vital organs often require treatment. Options range from medications to shrink fibroids to surgical procedures such as myomectomy or hysterectomy to remove fibroids. If you have uterine fibroids and concerns about possible compression of other organs, be sure to discuss your symptoms with your gynecologist.