Uterine fibroids are non-cancerous growths that develop from the muscle tissue of the uterus. They are common, affecting a large percentage of women during their reproductive years, though many remain unaware they have them. For those who do experience symptoms, changes in menstrual patterns represent the most frequently reported issue. This often leads to concerns about whether these growths are responsible for disruptive or heavy blood loss.
The Direct Link: Do Fibroids Cause Abnormal Bleeding?
Fibroids are a common source of abnormal uterine bleeding. Their presence can disrupt the normal menstrual cycle. The severity and type of bleeding often depend on the number of fibroids present, their size, and, most importantly, their specific location within the uterine structure. Fibroids are recognized as one of the most frequent underlying conditions for heavy menstrual bleeding.
Different Types of Abnormal Bleeding
Fibroids can manifest as various alterations to a typical menstrual cycle, impacting both the volume and timing of blood loss. The most common presentation is menorrhagia, characterized by excessive menstrual blood loss that can interfere with daily life. This heavy flow is typically defined as bleeding that is substantially greater than usual.
Periods may also become prolonged, lasting seven days or more, which extends the overall duration of the monthly bleeding phase. Fibroids may also cause intermenstrual bleeding, which is bleeding or spotting that occurs between expected periods. These varied patterns of abnormal flow can make tracking a cycle challenging and often lead to fatigue due to chronic blood loss.
How Fibroids Physically Cause Bleeding
The mechanism for fibroid-related bleeding is complex, involving mechanical, vascular, and tissue changes within the uterus. Fibroids that grow just beneath the uterine lining, known as submucosal fibroids, are the most likely to cause severe blood loss because they directly distort and disrupt the delicate endometrial tissue. As the mass grows, it can increase the total surface area of the uterine lining that sheds each month, leading to a greater volume of menstrual fluid.
The presence of a fibroid mass impairs the uterus’s ability to contract effectively to constrict blood vessels and stop the flow of blood during menstruation. This failure of muscle contraction means the blood vessels remain open longer than they should, resulting in prolonged bleeding. Furthermore, fibroids promote a process called aberrant angiogenesis, which involves the formation of new, often chaotic and fragile blood vessels in the tissue surrounding the tumor. These abnormal vessels are prone to rupture and leakage, contributing to the heavy and sustained flow.
When to Consult a Physician About Bleeding
Any change in your typical bleeding pattern that is persistent or causes concern warrants a medical evaluation to determine the cause. Signs that the bleeding may be excessive include needing to change a pad or tampon every hour or two for several consecutive hours. Passing blood clots that are larger than the size of a quarter is another indicator of abnormally heavy flow that requires attention.
Chronic or severe blood loss can quickly lead to iron-deficiency anemia, which manifests as persistent fatigue, weakness, dizziness, or shortness of breath. If these signs are present, a physician should be consulted promptly to test blood iron levels and address the underlying cause of the blood loss. Appropriate management can then be put in place.