Uterine fibroids are non-cancerous growths composed of smooth muscle cells and fibrous connective tissue that develop within or on the wall of the uterus. Also known as leiomyomas or myomas, these growths affect a large percentage of women during their reproductive years. While many individuals experience no noticeable symptoms, fibroids can significantly impact gynecological health. The presence of fibroids often leads to patterns of bleeding described as irregular.
Understanding Uterine Fibroids
Fibroids are categorized based on where they are situated within the muscular structure of the uterus, and their location largely determines the nature of any potential symptoms. The three main types are submucosal, intramural, and subserosal, each corresponding to a different layer of the uterine wall. Submucosal fibroids develop directly beneath the endometrium. Because of their position, even small submucosal fibroids can cause significant issues with bleeding.
Intramural fibroids are the most frequently diagnosed type, growing entirely within the myometrium, the thick muscular wall of the uterus. As they increase in size, they can cause the uterus to expand and may influence the organ’s overall function. Subserosal fibroids are located on the outside surface of the uterus, just beneath the outer covering. These cause fewer menstrual problems but are more likely to create pressure symptoms by pressing on nearby organs like the bladder or bowels.
Some fibroids, both submucosal and subserosal, can be pedunculated, meaning they are attached to the uterus by a narrow stalk. The size and location of any fibroid are the primary factors that dictate whether a person will experience symptoms. The structural changes caused by these growths set the stage for the menstrual irregularities that often prompt a visit to a healthcare provider.
How Fibroids Disrupt the Menstrual Cycle
The term “irregular periods” in the context of fibroids most frequently refers to bleeding that is abnormally heavy and prolonged. This excessive bleeding is not typically a change in cycle timing, but a severe disruption to the expected flow and duration of the menses. Submucosal and large intramural fibroids are the most likely culprits for this type of menstrual abnormality. The presence of these growths can increase the overall surface area of the endometrium, meaning there is more tissue to shed, which results in greater blood loss.
Fibroids can interfere with the uterus’s ability to regulate and stop the bleeding once menstruation begins. The uterus normally contracts after shedding its lining to compress the blood vessels and staunch the flow, but fibroids can disrupt the uniform muscle structure of the myometrium, preventing these contractions. This impaired mechanical action means the bleeding continues longer than it should, resulting in prolonged periods.
The growths can also affect the vascular structure. Fibroids may increase the number of blood vessels in the surrounding uterine tissue and can cause congestion by compressing veins, which contributes to heavier bleeding. Fibroids can alter the production of certain growth factors and chemical mediators, such as prostaglandins, that regulate blood flow and clotting within the pelvis. This combination of physical and biochemical effects leads to the characteristic pattern of heavy and lengthy bleeding perceived as an irregular menstrual cycle.
Diagnosis and Symptom Management
If a person experiences consistently heavy or prolonged bleeding, the first step is a consultation with a healthcare provider to determine the cause. The diagnostic process begins with a pelvic examination, where a doctor can sometimes feel an enlarged or irregularly shaped uterus, suggesting the presence of fibroids. This is followed by imaging tests to confirm the diagnosis, map the location, and measure the size of the growths.
The most common initial imaging tool is an ultrasound, which uses sound waves to create a picture of the uterus and ovaries. A transvaginal ultrasound, where the probe is placed inside the vagina, often provides more detailed images of the uterine wall and cavity than an abdominal ultrasound. For a clearer view of submucosal fibroids, a sonohysterography may be performed, which involves injecting saline solution into the uterine cavity during an ultrasound to distend the walls.
Management focuses on controlling the symptoms, particularly the heavy bleeding, and options range from medication to surgical procedures. Nonsteroidal anti-inflammatory drugs (NSAIDs) can reduce blood flow and cramping. Hormonal birth control methods, such as oral contraceptives or hormonal intrauterine devices (IUDs), can stabilize the uterine lining and decrease the volume of menstrual flow. Other medications like tranexamic acid help promote blood clotting to reduce the severity of the bleeding.
For severe symptoms or when fertility preservation is desired, a myomectomy, which is the surgical removal of the fibroids while leaving the uterus intact, may be recommended. If symptoms are debilitating and childbearing is complete, a hysterectomy, the removal of the entire uterus, remains a definitive treatment option. The choice of treatment is individualized, depending on the person’s symptoms, the size and location of the fibroids, and their future reproductive plans.