If you’ve been experiencing painful periods, pelvic pain, pain during sex or difficulty falling pregnant, you may have had an ultrasound to look for a possible cause.
And sometimes the result comes back as “normal”.
For many women, that can be reassuring. But if your symptoms are continuing, it can also leave you wondering: If my ultrasound is normal, does that mean I definitely don’t have endometriosis?
The short answer is no.
A normal ultrasound does not always rule out endometriosis.
What is endometriosis?
Endometriosis is a condition where tissue similar to the lining of the uterus grows outside the uterus.
It can occur in different areas of the pelvis, including around the ovaries, fallopian tubes, pelvic lining, bowel and bladder.
Endometriosis can cause inflammation, scarring and adhesions, although the way it affects each person varies considerably.
Some people have extensive endometriosis with relatively few symptoms. Others can have significant pain despite having only small or superficial areas of disease.
This is one of the reasons endometriosis can sometimes be difficult to diagnose.
What can an ultrasound detect?
A pelvic ultrasound is an important part of investigating pelvic pain and suspected endometriosis.
When performed by an experienced sonographer, particularly using transvaginal ultrasound, it can sometimes identify features associated with endometriosis.
These may include:
ovarian endometriomas, sometimes called “chocolate cysts”
deeper areas of endometriosis involving structures within the pelvis
signs that pelvic organs are not moving freely because of adhesions
other conditions that may be contributing to symptoms, such as fibroids or ovarian cysts.
For some patients, ultrasound can provide very useful information and help guide treatment or surgical planning. However, ultrasound has limitations.
Why can endometriosis be missed on ultrasound?
Not all forms of endometriosis are easy to see on imaging.
In particular, superficial endometriosis can involve small or thin areas on the surface of the pelvic lining. These changes may not be visible on a standard pelvic ultrasound.
This means it is possible to have symptoms consistent with endometriosis even when your ovaries, uterus and other pelvic structures appear normal on the scan.
The quality of the ultrasound also matters.
A routine pelvic ultrasound and an ultrasound specifically assessing for endometriosis are not always the same thing. Specialist imaging may involve a more detailed assessment of the way pelvic organs move and a closer examination of areas where deep endometriosis commonly occurs. Even with specialist imaging, however, not every case can be identified.
Does the severity of my pain tell you how much endometriosis I have?
Not necessarily.
One of the frustrating things about endometriosis is that the amount of disease seen on imaging or during surgery does not always match the severity of someone’s symptoms.
A person with relatively limited endometriosis can experience significant pain, while another person with more extensive disease may have few symptoms.
Pain can also become more complex over time.
Endometriosis may be one contributor, but pelvic floor muscle tension, bladder or bowel conditions, nerve sensitivity and other causes of pelvic pain can sometimes occur alongside it.
That is why we treat the person and their symptoms, not simply the scan result.
What symptoms might suggest endometriosis?
Endometriosis can present differently from person to person, but symptoms may include:
periods that are significantly painful or interfere with normal activities
pelvic pain at other times of the month
pain during or after sex
pain with bowel movements, particularly around your period
pain when passing urine around your period
heavy or irregular bleeding
difficulty falling pregnant
ongoing abdominal or pelvic discomfort.
Period pain that regularly causes you to miss work, school, exercise or social
activities is worth discussing with your doctor.
Severe pain should not simply be dismissed as something you have to put up with.
What happens if my ultrasound is normal but my symptoms continue?
A normal scan is one piece of information. It should not be the end of the
conversation if your symptoms are continuing to affect your quality of life.
Your doctor may talk with you about your symptoms in more detail, including when the pain occurs, whether it changes throughout your menstrual cycle and whether you have bladder, bowel or fertility concerns.
Depending on your individual circumstances, management may include pain relief, hormonal treatment, pelvic physiotherapy or further assessment.
Some people may also benefit from specialist imaging or referral to a gynaecologist with experience in endometriosis.
Historically, laparoscopy — keyhole surgery — was often considered necessary to confirm endometriosis. Today, diagnosis and treatment are increasingly based on a combination of symptoms, clinical assessment and imaging, and surgery is not automatically required for everyone.
For some patients, however, laparoscopy may still be appropriate, particularly when symptoms remain significant despite treatment, fertility is a concern, imaging suggests more complex disease or there are other reasons surgery may be beneficial.
The decision is individual.
Could something else be causing my symptoms?
Yes. Absolutely. This is another reason a thorough assessment is important.
Pelvic pain can have many possible causes, including adenomyosis, ovarian cysts, fibroids, pelvic floor dysfunction, bladder conditions and gastrointestinal disorders such as irritable bowel syndrome.
Sometimes more than one condition is contributing at the same time.
Investigating pelvic pain is therefore not simply about finding, or ruling out, endometriosis. The aim is to understand what may be driving your symptoms and find a management approach that works for you.
The important thing to remember
If your ultrasound is normal but you are still experiencing significant pelvic pain or other symptoms associated with endometriosis, your symptoms still deserve to be investigated.
A normal ultrasound can rule out some conditions and provide useful reassurance, but it cannot exclude every form of endometriosis.
You know when something does not feel right in your body.
If pain is regularly interfering with your periods, sex, work, exercise, bowel or bladder function, fertility or everyday life, speak with your GP or gynaecologist about the next step.
There are options for further assessment and treatment, and you do not need an abnormal ultrasound result before starting that conversation.
By Dr Abby Evans