Uterine polyps are growths found in the lining of the uterus that can cause cramping and pelvic pain. This discomfort often presents as a dull ache or sharp cramping, mimicking typical menstrual pain (dysmenorrhea). While abnormal bleeding is the most common symptom, polyps can lead to significant pain. These growths are usually benign but cause physical and biochemical reactions that result in painful sensations.
What Exactly Are Uterine Polyps?
Uterine polyps, also called endometrial polyps, are an overgrowth of the endometrial tissue lining the uterus. They attach to the inner uterine wall, projecting into the uterine cavity either by a thin stalk (pedunculated) or a broad base (sessile). These growths vary greatly in size, from a few millimeters to several centimeters.
The vast majority of uterine polyps are non-cancerous. They are composed of glandular tissue, fibrous stroma, and blood vessels, and are highly sensitive to the hormone estrogen. This sensitivity makes them more common during reproductive years and around menopause.
The Mechanism: Why Polyps Cause Cramping
The pain and cramping result from two distinct physiological processes: mechanical irritation and the body’s attempt at expulsion. The uterus is a muscular organ that perceives the polyp as an abnormal foreign object. The involuntary and intense contractions of the myometrium are the body’s reflex to try and push the polyp out of the cavity, which is felt as a cramp.
The polyp also causes mechanical irritation and localized inflammation in the surrounding endometrial tissue. This irritation leads to the release of inflammatory substances, primarily prostaglandins. Prostaglandins are hormone-like compounds that regulate pain and trigger uterine muscle contractions during a typical menstrual period. A polyp may also partially block the flow of menstrual blood, causing the uterus to contract even harder to overcome the obstruction, thereby increasing the intensity of the cramping.
Other Key Indicators of Uterine Polyps
The most frequently reported indicator of a uterine polyp is abnormal uterine bleeding. This can manifest as heavy menstrual flow (menorrhagia) or intermenstrual bleeding, which is spotting between expected cycles.
Other common symptoms include bleeding after sexual intercourse or any vaginal spotting that occurs after menopause. Polyps can also cause a clear or whitish vaginal discharge. In some cases, polyps interfere with fertility by physically blocking the fallopian tubes or altering the uterine environment.
Diagnosis and Treatment Options
If a polyp is suspected based on symptoms like abnormal bleeding or persistent cramping, diagnosis typically begins with imaging. A transvaginal ultrasound is a common first step, though polyps can be obscured by the uterine lining. A more precise method is a sonohysterography (Saline Infusion Sonogram or SIS), where sterile saline is introduced to gently distend the cavity, allowing the polyp to be clearly outlined and visualized.
The most definitive procedure for both diagnosis and treatment is a hysteroscopy. This involves inserting a thin, lighted telescope through the cervix to directly visualize the polyp and surrounding tissue. Treatment for symptomatic polyps involves removal through a procedure called a polypectomy, which is usually performed during the hysteroscopy using specialized instruments. Removing the polyp generally resolves the associated cramping and abnormal bleeding.