How Are Fibroids Diagnosed?
Understanding the Tests and Examinations Used to Diagnose Uterine Fibroids
Introduction
Many women don't realise they have fibroids until they're discovered during a routine examination or an ultrasound scan performed for another reason.
Others seek medical advice because they're experiencing heavy periods, pelvic pain or difficulty becoming pregnant, and fibroids are identified during investigations.
If you've been told you have fibroids, you may wonder how doctors know for certain. Can they be felt during an examination? Do you always need a scan? Are blood tests helpful?
Unlike some medical conditions, diagnosing fibroids is usually straightforward. Modern imaging techniques allow healthcare professionals to see the uterus in remarkable detail, making it possible to identify the number, size and location of fibroids.
However, diagnosis involves more than simply finding a fibroid. Your healthcare professional also needs to determine whether the fibroids are responsible for your symptoms, whether further investigations are needed and whether treatment is likely to benefit you.
This article explains how fibroids are diagnosed, what tests you may be offered and what your results might mean.
Quick Summary
Fibroids are often suspected from your symptoms and confirmed with imaging.
An ultrasound scan is usually the first and most important test.
A pelvic examination may detect larger fibroids.
Additional investigations, such as MRI or hysteroscopy, may be recommended in some cases.
Blood tests cannot diagnose fibroids but can identify complications such as iron deficiency anaemia caused by heavy menstrual bleeding.
Many fibroids are discovered accidentally during scans performed for unrelated reasons.
When Might Fibroids Be Suspected?
Fibroids don't always cause symptoms.
In fact, many women only discover they have fibroids after having an ultrasound during pregnancy or while investigating fertility problems.
When symptoms do occur, they often include:
Heavy or prolonged menstrual bleeding.
Pelvic pain or pressure.
A feeling of fullness in the lower abdomen.
Frequent urination.
Constipation.
Pain during sexual intercourse.
Difficulty becoming pregnant or recurrent miscarriage in some women.
These symptoms don't automatically mean you have fibroids. Many other conditions, including adenomyosis, endometriosis and ovarian cysts, can cause similar problems.
That's why further assessment is important.
Your Medical History
The first step is usually a detailed conversation about your symptoms.
Your healthcare professional may ask questions such as:
How heavy are your periods?
How long do they last?
Do you pass large blood clots?
Are your periods painful?
Do you feel pressure in your pelvis?
Are you needing to pass urine more frequently?
Have you noticed constipation or bloating?
Are you trying to become pregnant?
Have you experienced previous miscarriages?
Has anyone else in your family had fibroids?
Although these questions may seem simple, they help build a picture of how fibroids may be affecting your daily life.
Pelvic Examination
Your doctor may recommend a pelvic examination.
During this examination, they gently feel the uterus through the abdomen and vagina to assess its size and shape.
Large fibroids may make the uterus feel enlarged, irregular or firmer than expected.
However, many smaller fibroids cannot be detected by examination alone.
A normal examination therefore does not rule out fibroids.
Ultrasound Scan
An ultrasound scan is the main investigation used to diagnose fibroids.
It is safe, painless and does not involve radiation.
Ultrasound uses high-frequency sound waves to create images of the uterus and surrounding organs.
The scan helps determine:
Whether fibroids are present.
How many fibroids there are.
Their size.
Their exact location.
Whether they may be affecting the cavity of the womb.
This information is essential when deciding whether treatment is needed.
Transabdominal Ultrasound
This scan is performed through the lower abdomen using a probe placed on the skin.
It provides a good overall view of the uterus and is particularly useful for larger fibroids.
Transvaginal Ultrasound
For many women, a transvaginal ultrasound provides much clearer images.
A slim ultrasound probe is gently inserted into the vagina, allowing the uterus to be viewed from much closer range.
Although some women feel anxious beforehand, the procedure is usually well tolerated and often provides the most accurate information about smaller fibroids.
MRI Scan
Most women do not need an MRI scan.
However, your doctor may recommend one if:
You have several fibroids.
Very large fibroids are present.
Surgery is being planned.
The ultrasound findings are unclear.
The exact position of fibroids needs to be mapped before treatment.
MRI produces highly detailed images of the uterus and surrounding tissues.
It can help surgeons plan procedures more accurately and distinguish fibroids from conditions such as adenomyosis.
Hysteroscopy
If your symptoms suggest a fibroid is growing inside the cavity of the uterus, your doctor may recommend a hysteroscopy.
This involves passing a thin telescope through the cervix into the uterus.
Unlike an ultrasound, hysteroscopy allows the doctor to look directly inside the womb.
It is particularly useful for identifying submucosal fibroids, which grow beneath the lining of the uterus and may contribute to heavy bleeding, infertility or recurrent miscarriage.
In some cases, small fibroids can even be removed during the same procedure.
Blood Tests
Blood tests cannot diagnose fibroids.
However, they are often recommended because fibroids—particularly those causing heavy menstrual bleeding—can lead to complications.
Your doctor may request tests such as:
Full Blood Count (FBC)
Heavy periods can result in iron deficiency anaemia.
A full blood count checks whether your haemoglobin level is low.
Iron Studies
If anaemia is suspected, iron levels may also be measured to determine whether iron replacement is needed.
Additional blood tests may sometimes be performed to rule out other causes of abnormal bleeding, depending on your symptoms.
Can Fibroids Be Missed?
Occasionally, yes.
Very small fibroids may not cause symptoms and can sometimes be difficult to detect, particularly if imaging quality is limited.
In other cases, symptoms caused by fibroids may initially be attributed to other conditions.
Fortunately, modern ultrasound technology is highly effective at identifying most clinically significant fibroids.
If symptoms continue despite normal initial investigations, your doctor may recommend further imaging or referral to a specialist.
Could It Be Something Else?
Several conditions can cause symptoms similar to fibroids.
These include:
Adenomyosis.
Endometriosis.
Ovarian cysts.
Endometrial polyps.
Pelvic inflammatory disease.
Less commonly, cancers of the uterus or ovaries.
This is one reason why imaging is so important—it helps identify the true cause of your symptoms and ensures you receive the most appropriate treatment.
What Happens After Diagnosis?
Finding a fibroid doesn't automatically mean treatment is needed.
Your healthcare professional will consider:
Whether your fibroids are causing symptoms.
Their size and location.
Whether they're growing.
Your age.
Whether you hope to become pregnant in the future.
How much your symptoms affect your quality of life.
Many women simply need regular monitoring.
Others may benefit from medication, minimally invasive procedures or surgery.
The right approach depends on your individual circumstances rather than the fibroids alone.
Why Early Assessment Matters
Heavy periods, pelvic pressure and persistent pain should never be dismissed as "just part of being a woman."
Although fibroids are a common cause of these symptoms, they're not the only possible explanation.
Seeking medical advice allows the underlying cause to be identified and, if necessary, treated before complications such as iron deficiency anaemia or fertility problems develop.
Even if your symptoms turn out not to be caused by fibroids, you deserve to understand what's happening in your body.
Key Takeaways
Fibroids are usually diagnosed using ultrasound.
A pelvic examination may detect larger fibroids but cannot rule out smaller ones.
MRI and hysteroscopy may be recommended in selected cases.
Blood tests don't diagnose fibroids but can identify complications such as anaemia.
Many fibroids are found by chance and never require treatment.
Diagnosis is about understanding not only whether fibroids are present, but whether they are responsible for your symptoms.
Frequently Asked Questions
Can fibroids be diagnosed without a scan?
Sometimes larger fibroids can be suspected during a pelvic examination, but an ultrasound is usually needed to confirm the diagnosis and determine their size and location.
Is a transvaginal ultrasound painful?
Most women find it uncomfortable rather than painful. The probe is slim and is inserted gently into the vagina. If you have concerns, let the person performing the scan know—they can usually make adjustments to help you feel more comfortable.
Can blood tests detect fibroids?
No. Blood tests cannot diagnose fibroids, but they can show whether heavy menstrual bleeding has caused anaemia or iron deficiency.
If fibroids are found by chance, do they need treatment?
Not necessarily. Many fibroids cause no symptoms and don't require treatment. Your healthcare professional will consider your symptoms, the size and location of the fibroids, and whether they're affecting your health or fertility before recommending any intervention.
References
This article should reference high-quality, evidence-based sources including:
National Institute for Health and Care Excellence (NICE)
Royal College of Obstetricians and Gynaecologists (RCOG)
American College of Obstetricians and Gynecologists (ACOG)
European Society of Human Reproduction and Embryology (ESHRE)
Peer-reviewed research on imaging, diagnosis and management of uterine fibroids.