How is endometriosis diagnosed?

Around one in 10 women in the UK, aged between 16 and 50, have endometriosis. It occurs when the tissue that lines your womb (endometrial tissue) grows outside your womb, usually around your ovaries, fallopian tubes and pelvic area, although it can spread further to your bowel.  

Before we look at how endometriosis is diagnosed, it’s helpful to understand what this condition does to your body.

Your menstrual cycle and endometriosis

During your menstrual cycle, changes in your hormones cause your endometrial tissue to thicken. When you have a period, the endometrial tissue lining your womb tissue breaks down and is released through your vagina as menstrual bleeding. However, if you have endometrial tissue elsewhere, it can’t leave your body and this causes the symptoms of endometriosis. 

Trapped endometrial tissue irritates surrounding tissues and causes thick bands of scar tissue to form — these are called adhesions. Adhesions can cause chronic (long-term) pain, which may get worse during your period. 

Endometriosis symptoms

Common endometriosis symptoms include pelvic pain and pain in your lower back and tummy. However, depending on where the abnormal endometrial tissue has spread in your body, you may also find urinating and passing stools painful just before, during or just after your period. Sex can become painful too.

You may also notice that your periods become heavy and that you bleed in between your periods. In more severe cases of endometriosis, you may find it difficult to become pregnant or you may become infertile.

Endometriosis diagnosis

The symptoms of endometriosis vary a lot between women. Endometriosis can also be mistaken for other conditions, such as a bladder infection, fibroids and pelvic inflammatory disease. Taken together, this can make diagnosing endometriosis difficult. According to the charity Endometriosis UK, after seeing a doctor about symptoms, women on average get a clear diagnosis of endometriosis after seven and a half years.

Testing for endometriosis

If you’re concerned that you have endometriosis, you may be wondering what an endometriosis test involves. The first step is to see your GP. They will discuss your symptoms and may then recommend a number of different tests — such as a pelvic exam, ultrasound scan or MRI scan — to eliminate other causes of your symptoms. 

The only definitive endometriosis test involves a minor surgical procedure called a laparoscopy. Your GP may therefore suggest other less invasive tests first before deciding whether you need to have a laparoscopy. 

Can ultrasound diagnose endometriosis?

Your GP may recommend an ultrasound scan of your abdomen to help diagnose endometriosis. Ultrasound scans can’t definitively confirm whether you have the condition but may pick up signs of endometriosis, specifically endometriomas, also known as ‘chocolate cysts’ — these cysts occur in 20-40% of women with endometriosis.

There are two types of ultrasound scans that you may have to help diagnose endometriosis: a standard ultrasound scan of your abdomen or a transvaginal ultrasound scan. Both use a handheld device called a transducer, which generates sound waves and also detects them as they bounce back from your body — this creates detailed images of the inside of your body. 

During a standard ultrasound scan, the transducer is moved over your abdomen. During a transvaginal ultrasound scan, the transducer, which is slightly wider than a finger, is inserted into your vagina. Both can produce detailed images of your womb, ovaries and fallopian tubes. 

Pelvic exam

Your GP may carry out a pelvic exam to investigate your symptoms. They will use a gloved hand to feel the outside and the inside of your womb — this involves them inserting one or two fingers into your vagina. This will allow them to check for cysts, adhesions and unusual growths. 

If the patches of endometrial tissue that have grown outside your womb are still small, it may not be possible for your GP to detect them using a pelvic exam. 

MRI scans

An MRI scan uses radio waves and strong magnets to capture detailed images of the inside of your body. It can help detect endometrial tissue that has grown outside of your womb but, as with an ultrasound scan, can’t definitely confirm whether you have endometriosis.

If ‘chocolate cysts’ were detected on your ultrasound scan and need to be removed, an MRI scan may be recommended. It can provide more details on the size and location of your cysts, which can help your surgeon plan how to proceed with your surgery. 

Laparoscopy

A laparoscopy is the only definitive endometriosis test and is used to determine the extent of your condition, and the size and location of any patches of endometrial tissue outside your womb. It is a type of keyhole surgery, which means only small cuts are needed and is carried out under a general anaesthetic.

A surgeon will make a small cut into your tummy and insert a thin, telescope-like tube with a light and camera at the end (a laparoscope) into your abdomen. This allows them to see inside your abdomen and check for endometrial tissue outside your womb.

In some cases, further small cuts may be made so your surgeon can collect tissue samples (biopsies) by inserting surgical instruments. These biopsies are examined in a lab to confirm endometriosis. Your surgeon may also decide to remove any endometrial tissue they find outside your womb during your laparoscopy so you won’t need to have another surgery to do this.

Misdiagnosis of endometriosis

One of the reasons why endometriosis goes undiagnosed for, on average, seven and a half years after symptoms start is often because it is misdiagnosed. One research study in Germany and Austria revealed that almost three-quarters of women with endometriosis had at least one misdiagnosis. 

Some women who have lived for years with undiagnosed endometriosis, despite seeking medical help for their symptoms, do not believe their symptoms were taken seriously. For other women, the fact that their symptoms overlapped with other conditions led to a misdiagnosis. 

Conditions with symptoms similar to endometriosis include: 

• A bladder infection
• Irritable bowel syndrome
• Musculoskeletal problems
• Ovarian cysts and uterine fibroids
• Pelvic inflammatory disease (PID)
• Psychosexual problems

Managing your diagnosis

Before your first appointment with a doctor, consider the severity and frequency of your symptoms and have key information about your health and menstrual cycle to hand. To help with this you can fill out the 'your first consultation' questionnaire from Endometriosis UK.

Make sure you also track your symptoms and their severity on a scale of one to 10. You can do this by keeping a diary, using the 'pain and symptoms' diary from Endometriosis UK or using a period-tracking app. If you want to use an app, find one that lets you track specific symptoms. 

Common endometriosis treatments

The right endometriosis treatment for you will depend on the severity of your symptoms. Here are four endometriosis treatment options: 

1. Home remedies

Taking warm baths and applying a heat pad can reduce cramping and pelvic pain by relaxing your muscles. You can also take over-the-counter painkillers to manage your pain — these include nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen.

2. Hormone treatments

These work by reducing or stopping production of the sex hormone oestrogen, which is what causes endometrial tissue to grow. There are several different options, including the birth control pill or injection and the hormonal intrauterine device (IUD) — these will also prevent you from getting pregnant. 

Other hormone treatments include gonadotropin-releasing hormone (Gn-RH) therapy and aromatase inhibitors — when taking these drugs, you should use a non-hormonal contraceptive (eg condom or diaphragm) when having sex.

3. Surgery

The most common surgery to treat endometriosis is a laparoscopy. This is a type of keyhole surgery used to carefully remove endometrial tissue outside your womb. If other treatments aren’t effective and your endometriosis is severe, your doctor may recommend surgery to remove your womb (hysterectomy) and in some cases, your ovaries too (oophorectomy) — you will not be able to get pregnant after this. 

4. Alternative medicine

Some women with endometriosis have found acupuncture helpful in managing their pain. However, there is no comprehensive research to support whether it really is effective or not. 

Pregnancy and endometriosis

If you have endometriosis and are struggling to get pregnant, speak to your GP or a gynaecologist (a doctor specialising in women’s health) about fertility treatments.