Fibroids are typically found through a combination of a pelvic exam and an ultrasound, which together can detect nearly all fibroids with about 99% sensitivity. Some women discover fibroids after reporting symptoms like heavy periods or pelvic pressure, while others learn about them incidentally during a routine exam. Here’s what the diagnostic process looks like from start to finish.
What Your Doctor Checks During a Pelvic Exam
The first step is usually a bimanual pelvic exam, where your doctor places two gloved fingers inside the vagina while pressing on your lower abdomen with the other hand. This lets them feel the size, shape, and mobility of your uterus. Fibroids can make the uterus feel enlarged, lumpy, or irregularly shaped instead of its normal pear size and smooth contour. A doctor performing an abdominal exam may also feel a large fibroid through the belly wall if it has grown significantly.
A pelvic exam alone can raise suspicion, but it can’t confirm the diagnosis or tell your doctor exactly how many fibroids you have, where they’re located, or how big they are. That’s why imaging almost always follows.
Pelvic Ultrasound: The Standard First Test
A pelvic ultrasound is the go-to imaging tool for confirming fibroids. It uses sound waves to create a picture of your uterus, and it picks up fibroids with 99% sensitivity and 91% specificity. In other words, it catches nearly every fibroid and rarely mistakes something else for one. There are two types, and you may get both in the same visit.
A transabdominal ultrasound uses a wand pressed against your lower belly. You’ll need a full bladder for this one. Johns Hopkins recommends drinking at least 24 ounces of clear fluid an hour before your appointment and holding it until the exam is done. A full bladder pushes the uterus into a better position and moves the bowel out of the way so the image is clearer.
A transvaginal ultrasound uses a slim probe inserted into the vagina, which gets much closer to the uterus and produces more detailed images. For this part, you empty your bladder right beforehand. It’s more useful for mapping the exact size, number, and position of fibroids. The whole process typically takes 15 to 30 minutes and isn’t painful, though you may feel some pressure.
Saline Sonogram for a Closer Look Inside
If your doctor suspects a fibroid is growing into the inner cavity of your uterus (called a submucosal fibroid), they may order a saline infusion sonogram, sometimes called a sonohysterogram. This type of fibroid can cause the heaviest bleeding and may interfere with fertility, so getting a clear view matters.
During this test, your doctor inserts a thin catheter through the cervix and fills your uterus with sterile saline while performing a transvaginal ultrasound at the same time. The fluid expands the uterine cavity, making it much easier to see whether a fibroid is bulging into the space where a pregnancy would implant. You can expect some cramping and pressure during the procedure, similar to period cramps, but it’s quick. The catheter and ultrasound wand are removed as soon as the images are captured.
When an MRI Is Needed
Most fibroids are fully diagnosed with ultrasound alone. An MRI is reserved for situations where ultrasound doesn’t give a clear enough picture, usually when the uterus is very large, contains many fibroids, or when your doctor needs to distinguish fibroids from a condition called adenomyosis that can look similar on ultrasound and cause overlapping symptoms.
On MRI, fibroids appear as well-defined, round masses with sharp borders that compress the surrounding muscle tissue, creating a visible outline called a pseudocapsule. Adenomyosis, by contrast, shows up as a poorly defined, oval-shaped area that blends into the uterine wall without clear edges. Fibroids also commonly have dilated blood vessels at their borders (seen in about 42% of cases), while adenomyosis does not. These distinctions matter because the two conditions are treated differently.
An MRI is also commonly ordered before certain procedures like uterine artery embolization, where the interventional radiologist needs a precise map of every fibroid’s location and blood supply.
Hysteroscopy: Direct Visualization
A hysteroscopy lets your doctor look directly inside the uterus using a thin, lighted telescope inserted through the cervix. Saline is used to expand the cavity so the walls are clearly visible. This is typically reserved for cases where imaging suggests a submucosal fibroid and your doctor wants to confirm its size and position before planning removal.
The advantage of hysteroscopy is that it can be both diagnostic and therapeutic. If a submucosal fibroid is found, it can sometimes be removed during the same procedure using instruments passed through the hysteroscope, avoiding the need for a separate surgery.
Blood Tests That Support the Diagnosis
Fibroids themselves don’t show up on a blood test, but your doctor will likely order lab work to check for complications. The two most common tests are a complete blood count (CBC) and iron levels. Heavy menstrual bleeding from fibroids frequently leads to iron-deficiency anemia, and these tests reveal whether your red blood cell count or iron stores have dropped. A pregnancy test is also standard to rule out pregnancy as a cause of an enlarged uterus or missed periods.
If your bleeding pattern is unusual or you have risk factors for other conditions, your doctor may also recommend an endometrial biopsy to rule out abnormal cell growth in the uterine lining. This is a precautionary step, not a fibroid test itself.
Tracking Symptoms Before Your Appointment
If you suspect fibroids, tracking your symptoms before your visit gives your doctor useful information to work with. The details that matter most include how heavy your periods are (how often you change pads or tampons, whether you pass clots), how many days your period lasts, whether you feel pelvic pressure or fullness, and whether your symptoms affect your energy, daily activities, or sex life.
Clinicians use a standardized questionnaire called the UFS-QOL that measures symptom severity across eight questions and quality of life across 29 more, covering areas like energy, mood, self-consciousness, and daily function. You probably won’t fill out this exact form, but thinking through those categories before your appointment helps you describe what you’re experiencing in a way that guides the right workup.
What the Diagnostic Path Looks Like Overall
The American College of Radiology outlines a straightforward sequence: physical exam first, then pelvic ultrasound or MRI to confirm the diagnosis and map fibroid location, size, and number. Additional tests like blood work, saline sonogram, or hysteroscopy are added based on your symptoms and what the initial imaging shows. Most women get their answer after just the pelvic exam and a standard ultrasound. The entire process, from first appointment to confirmed diagnosis, often happens within one or two visits.