Uterine fibroids are classified into four types based on where they grow: intramural, submucosal, subserosal, and pedunculated. Location determines everything, from the severity of bleeding and pelvic pressure to fertility implications and treatment approach. Having multiple fibroid types at once is common, and symptoms alone rarely reveal the full picture without proper imaging.
Uterine fibroids are far more common than many people realize, and yet they often go undiagnosed for years. Some women live with them without any noticeable symptoms, whereas others experience heavy bleeding, persistent pelvic pressure, or pain that quietly chips away at daily life.
At NG Vascular & Vein Center, we work with women who have been dealing with these symptoms for a long time before they get any answers. One of the first things to know is that there are different types of uterine fibroids. Where a fibroid grows significantly influences the symptoms it causes and how best to address it.
The 4 Types of Uterine Fibroids and What Sets Them Apart
Before getting into the individual types, it helps to know what fibroids actually are. Uterine fibroids are growths made of smooth muscle cells and fibrous connective tissue. They are noncancerous, and they can appear alone or in clusters. Size varies widely, too, ranging from something as small as a grain of rice to much larger.
Many doctors believe they develop when an abnormal muscle cell in the uterine wall begins multiplying under the influence of estrogen, eventually forming a benign tumor.
There are four main types, which are classified by where in or around the uterus they develop. Knowing which type you have matters because location shapes everything from your symptoms to your treatment options.
Intramural Fibroids: The Most Frequently Diagnosed Type
Intramural fibroids grow within the muscular wall of the uterus itself. They are the most commonly diagnosed fibroid type and can develop in several positions within the uterine wall, including the front, back, or upper portion. It is also common to find multiple intramural fibroids clustered in the same area.
As these fibroids grow, they can cause the uterus to appear larger than normal. Women with intramural fibroids often describe a sensation of pelvic fullness or pressure. When the fibroid becomes large enough to distort the uterus, it can also affect fertility and pregnancy outcomes.
Symptoms associated with intramural fibroids can include:
- Heavy or prolonged menstrual periods: bleeding that goes beyond what feels normal
- Pelvic pressure or fullness: a persistent feeling of weight in the lower abdomen
- Lower back pain, particularly when the fibroid is positioned toward the back of the uterus
- Abnormal uterine bleeding: bleeding that occurs outside of a normal cycle
Smaller intramural fibroids sometimes cause no symptoms, which is why they can go undetected for a long time.
Submucosal Fibroids: Less Common, But Often the Most Disruptive
Submucosal fibroids develop just beneath the inner lining of the uterus and extend into the uterine cavity. They tend to be smaller, but their location makes them particularly likely to cause significant symptoms. Even a small submucosal fibroid can lead to extremely heavy periods, prolonged bleeding, the passing of large clots, and severe cramping.
This fibroid type is also more associated with fertility challenges. Submucosal fibroids can interfere with implantation and raise the risk of miscarriage. Women who have been struggling with unexplained fertility difficulties sometimes discover that a submucosal fibroid is a contributing factor.
Some submucosal fibroids can also develop on a stalk, which can lead to them being mistaken for uterine polyps on imaging. A proper diagnosis from a specialist is key to distinguishing between the two.
Subserosal Fibroids: Growing Outward, Pressing Inward
Subserosal fibroids grow on the outer wall of the uterus and push outward into the pelvic cavity. Because they grow away from the uterine cavity, they tend not to cause heavy menstrual bleeding the way submucosal fibroids do. Their symptoms are more related to the pressure they place on nearby organs as they expand.
These fibroids can become quite large before causing noticeable discomfort, simply because there is more room for them to grow before they press against something. When symptoms do appear, they often include:
- Urinary frequency or urgency: pressure on the bladder can make it feel constantly full
- Constipation or bowel discomfort: when the fibroid presses against the bowel
- Pain during intercourse: depending on the fibroid’s size and position
- Back or pelvic pain: caused by the weight and position of the growth
If you’ve been experiencing these kinds of symptoms without a clear explanation, exploring the conditions we treat at our centers may help you start connecting the dots.
Pedunculated Fibroids: A Different Kind of Growth
Pedunculated fibroids are distinct from the other three types in how they attach to the uterus. Rather than growing directly from the uterine wall, they develop on a thin stalk that connects them to it. A pedunculated fibroid can grow on the outside of the uterus, or it can develop on a stalk beneath the inner lining and protrude into the uterine cavity.
The stalk is what makes this type particularly prone to causing sharp or sudden pain. If the stalk twists, it can cut off the blood supply to the fibroid, leading to intense, acute discomfort. Because of their shape and position, pedunculated fibroids can also be mistaken for ovarian masses on imaging, underscoring the importance of an accurate diagnosis.
Pedunculated fibroids are generally considered the least common of the four types, though women can have more than one type present at the same time.
What Happens When You Have More Than One Type?
It is entirely possible, and not uncommon, to have multiple fibroids of different types at once. One fibroid may be causing heavy bleeding while another is creating pressure on the bladder, making it difficult to pinpoint the source of each symptom. Because some fibroids can be very small, imaging may not detect all of them.
This is part of what makes a thorough evaluation so important. Symptoms alone can’t always paint the full picture. An ultrasound or other imaging study gives a much clearer view of what’s happening, how many fibroids are present, and where they are located.
When Fibroids Start Affecting How You Live
Living with fibroid symptoms can wear you down over time, and it’s worth taking seriously. Heavy bleeding, chronic pelvic pressure, bladder issues, and fertility concerns are not things to push through indefinitely without answers.
Uterine fibroid embolization is one treatment path worth exploring for women who want to address their fibroids without major surgery. It works by cutting off the blood supply to the fibroids, causing them to shrink over time. It’s an outpatient procedure, meaning no hospital stay, and recovery tends to be significantly shorter than with surgical alternatives.
Treatment decisions depend on the type of fibroids present, their size and location, and a woman’s health goals. A specialist conversation is the best place to start.
Heavy Periods and Pelvic Pain Are Worth Investigating
Living with unexplained symptoms and no clear diagnosis is frustrating. Knowing which fibroid type you have and how it’s affecting your body puts you in a much better position to make decisions about your care.
At NG Vascular & Vein Center, our approach is to give patients a clear picture of what’s going on and walk through options together. If fibroid symptoms have been affecting your quality of life, reach out and let’s have that conversation.
Book an appointment with us today.
FAQs
Do fibroids go away on their own?
Fibroids tend to shrink naturally after menopause when estrogen levels drop. Before that point, they generally do not disappear without treatment. Some remain stable for years, while others grow gradually and cause worsening symptoms over time.
How are uterine fibroids diagnosed?
A pelvic exam may raise initial suspicion, but imaging is needed to confirm a diagnosis. Ultrasound is the most common tool, providing a clearer view of fibroid size, number, and location. In some cases, additional imaging such as an MRI may be recommended.
Can fibroids affect pregnancy?
Certain fibroid types, particularly submucosal fibroids, can interfere with implantation or raise the risk of miscarriage. Larger intramural fibroids may also affect the uterine cavity. Women planning to conceive are encouraged to discuss any known fibroids with a specialist before attempting pregnancy.
