Diagnosing endometriosis

Photo of ultrasound diagnosis (PantherMedia / Iakov Filimonov)

Endometriosis is often only diagnosed and treated very late. If you are thought to have endometriosis, it is important to decide what examinations are actually needed. More invasive procedures such as an examination of the inside of your abdomen (laparoscopy) aren't always necessary when deciding how to best treat the symptoms. And they're associated with risks.

In women with endometriosis, the kind of tissue that lines the womb (endometrium) also grows in other parts of the body. This endometrial tissue is benign (non-cancerous) and doesn't always cause noticeable problems. Most women only seek medical help if the endometriosis causes a lot of pain or if they have difficulties getting pregnant.

The typical signs of endometriosis include severe period pain, pain during or after sex and tenderness in some areas of the pelvis.

Anamnesis and examination

The first thing doctors do is ask about the type of symptoms you are having. To help him or her get a clearer idea of the symptoms, it is important to carefully describe them in detail: when they started, how severe they are, where you notice them, how it feels, and when you have them. How the pain affects you may also play a role in deciding what needs to be done about the condition – for example, if it regularly disrupts your daily life and keeps you from doing typical activities, or if your love life is affected.

A general gynecological examination is the next step in arriving at a diagnosis. During the pelvic exam your doctor will check whether gently moving your womb and applying pressure to certain areas is painful. These may include the walls and supporting ligaments of the womb as well as the “Pouch of Douglas” between the womb and the rectum. Nodules and hard lumps in the pelvic connective tissue may also be a sign of endometriosis. But these may be caused by something else instead.

Before carrying out a pelvic exam, your doctor will put on sterile gloves. He or she will then feel your organs to find irregular shapes or hard areas by gently inserting one or two fingers into your vagina or anus while at the same time placing his or her other hand on top of your belly.

During a pelvic exam, the doctor usually has a look inside the vagina with the help of a medical instrument called a speculum as well. Only if the symptoms you have described and the pelvic exam (both feeling and looking) indicate that you have endometriosis can a decision be made about whether further diagnostic examinations are needed.


An ultrasound through the abdomen can detect signs of larger endometrial implants and cysts. The bladder and other organs can also be examined. An ultrasound exam through the vagina is more appropriate for determining whether you have ovarian endometriosis. Smaller endometrial implants and adhesions don't show up in ultrasound images, though.

If abnormal areas of tissue are found, it is sometimes possible to make a treatment decision based on these examinations. Whether or not further diagnostic examinations are needed will depend on how bad the symptoms are, as well as on other factors.


To be able to determine with some certainty whether you have endometriosis, a surgical procedure (laparoscopy) may be needed. This procedure is usually done with a general anesthetic. At least two small incisions (cuts) need to be made in the abdomen. The doctor inserts an instrument with a light and a tiny video camera at the end of it through a cut near the belly button. The camera provides images of the organs in the abdominal and pelvic cavities, making it possible to find even small areas of endometrial tissue and adhesions.

A second cut is normally made above and next to the pubic hairline. Instruments can be inserted through this cut to remove individual endometrial implants and take tissue samples.

Laparoscopy can be used to rule out endometriosis quite reliably: If no implants are found, it is unlikely that there is undetected endometriosis.

If endometrial implants are discovered in the ovaries or nodules are found in the lesser pelvis during laparoscopy, a tissue sample is usually taken and examined under the microscope (biopsy). This can confirm that it is actually endometriosis, and not another disease or a (rare) cancerous tumor.

Like any other kind of surgery performed under anesthesia, a laparoscopy carries risks so it should only be considered if a clear diagnosis is needed in order to decide what kind of treatment a woman should have. This is the case if she has serious pain which interferes with her daily life and her quality of life, or if nearby organs are affected.

Due to the risk of possible side effects, treatment with hormone drugs like GnRH analogues is usually only started if the diagnosis has been confirmed using laparoscopy.

In women who are finding it difficult to get pregnant, other tests are normally carried out first. A laparoscopy is only performed if these tests are inconclusive and endometriosis is likely.

Other diagnostic procedures

Some women with endometriosis have higher levels of CA125 in their blood. But measuring this value or doing other blood tests doesn't help to get a clearer diagnosis or to clearly rule out endometriosis. So these values aren't that relevant for further decisions, and they usually aren't used in the diagnosis of endometriosis nowadays.

Depending on both the severity of symptoms and the results of the gynecological examination, it may be a good idea to examine the kidneys using ultrasound, or to look at the bladder or bowel using an endoscope. Imaging techniques are also sometimes used, but this isn't as common. These include computer tomography (CAT or CT) or magnetic resonance imaging (MRI).

Stages of endometriosis

The following categories are commonly used by doctors to assess the extent of the disease (the size and number of affected areas of tissue):

  • “Minimal” (Stage I),
  • “Mild” (Stage II),
  • “Moderate” (Stage III), and
  • “Severe” endometriosis (Stage IV).

But there are currently no categories that offer a good description of endometriosis symptoms. Basing the categories on the number and size of the endometrial implants isn't much use to women who have endometriosis because there is little connection between the extent of the condition and the severity of pain. Women who have a similar amount of endometriosis can be affected in very different ways.