Endometriosis Diagnosis: Symptoms, Process, and Blood Values

How diagnosis works today

The diagnosis of endometriosis has changed significantly in recent years. For a long time, laparoscopy was considered the only way to a reliable diagnosis. Today, a stepped, gentler approach is in the foreground, starting with a conversation and ultrasound.

Anamnesis: the conversation as a starting point

It all starts with a detailed conversation. The doctor asks about the type, intensity, and temporal course of the pain, the cycle, discomfort during sexual intercourse or defecation, and any desire to have children. A symptom diary is particularly helpful here. The described symptoms are not just a preliminary talk, but a central building block of the diagnosis.

Physical examination and ultrasound

The conversation is followed by a gynecological examination. The central imaging method is transvaginal sonography, i.e., ultrasound through the vagina. With the new S2k guideline 2025, it was explicitly defined as the primary method for diagnosis. This replaces laparoscopy as the first step, an important change that should make diagnosis faster and gentler.

With an experienced examiner, chocolate cysts on the ovaries, deeply infiltrating lesions, and adenomyosis, i.e., endometriosis in the uterine wall, can be well visualized with ultrasound. However, it is important to note: Superficial lesions in the abdominal cavity are often not visible on ultrasound. Therefore, an unremarkable finding does not rule out endometriosis.

MRI and laparoscopy: when they are still needed

Magnetic resonance imaging, or MRI for short, is used as a supplement, for example, in cases of unclear symptoms or for planning an operation. Laparoscopy remains important, but its role has shifted: today it is primarily useful when treatment is to be carried out at the same time, i.e., lesions are removed in the same procedure. A purely diagnostic laparoscopy without therapeutic benefit is increasingly viewed critically.

Where you can turn

The gynecological practice is usually the first point of contact. In the case of persistent or severe symptoms, unclear findings, or a desire to have children, a referral to a specialized endometriosis center can be useful. Such centers have experience with ultrasound diagnostics and surgical treatment and often work interdisciplinarily. You are allowed and should actively ask for a referral if you feel that your symptoms are not being taken seriously enough.

The Enzian classification

If endometriosis is diagnosed, the so-called Enzian classification helps to uniformly describe the location and extent of the lesions. This is the basis for individual therapy planning. For you as a patient, it is particularly important to know: The extent in the finding does not always say something about the severity of the symptoms. Some women with extensive lesions have little pain, others with small lesions have very severe pain.

What blood and hormone levels can tell us

Many women wish for a simple blood test that reliably detects endometriosis. So far, such a test does not exist. Nevertheless, laboratory and hormone levels play a meaningful role if one correctly assesses what they can and cannot do.

Why there is no simple endometriosis blood test

The most well-known marker in this context is CA-125. It can be elevated in endometriosis but is too non-specific for a diagnosis: it also increases in other diseases and is normal in many affected individuals. Current guidelines therefore advise against using CA-125 as a diagnostic test for endometriosis. Various new biomarkers and tests are being researched but are not yet established in clinical practice.

Why a hormone analysis is still useful

Endometriosis is a highly estrogen-dependent disease, and many affected individuals have additional hormonal issues such as menstrual cycle disorders, thyroid problems, or an unfulfilled desire to have children. A hormone analysis does not diagnose endometriosis, but it can reveal the overall hormonal picture, narrow down other causes for symptoms, and create a basis for further treatment and family planning.

This is primarily useful as a supplement to medical diagnostics, not as a replacement. Those who know their own hormone status can have a more informed conversation with their doctor and discuss cycle, family planning, and therapy options more specifically.

Which values are often considered

• Estrogen and progesterone, to assess the interplay of cycle hormones.
• Thyroid values, as thyroid disorders can cause similar symptoms and are common.
• Values related to ovarian reserve and the cycle, especially for those wishing to conceive.
• General values such as iron or vitamin D, which influence well-being and the symptom profile.

Which values are useful in individual cases depends on your situation and should be medically supervised. The interpretation remains important: hormone values provide context and help with therapy and family planning, but they are not proof for or against endometriosis.

How to prepare for the appointment

Good preparation can make the appointment significantly more productive. Beforehand, note down your main symptoms, when they occur, and how severe they are, ideally using a symptom diary over several cycles. Record which painkillers you take and how effective they are, and consider whether you wish to have children, as this influences the choice of diagnostics and therapy. Write down specific questions so you don't forget them during the appointment. Those who are prepared get the right next steps faster.

What you can take away from this knowledge

• Take severe or increasing menstrual pain seriously, especially if it impairs daily life.
• Keep a symptom diary for several cycles before the appointment.
• Know that ultrasound is now the first diagnostic step and a laparoscopy is not necessarily the first step.
• Do not expect proof from a blood test, but use a hormone analysis as a useful addition to the overall picture.

When you should seek medical advice

Severe or increasing menstrual pain, pain during intercourse, chronic pelvic pain, bladder or bowel symptoms during your period, or an unfulfilled desire to have children require medical evaluation. The sooner you address these symptoms, the sooner the often years-long diagnostic delay can be shortened.

Conclusion

Diagnosing endometriosis still takes too long, but the path to diagnosis is now clearer and less invasive than before. Since the new S2k guideline 2025, transvaginal sonography is the primary method, supplemented by MRI and, if necessary, a laparoscopy with simultaneous treatment. However, the most important factor remains yourself: take symptoms seriously, document them, and get them checked early.

Blood and hormone values cannot prove endometriosis. However, a hormone analysis can classify the overall hormonal picture, narrow down other causes, and provide valuable context, especially for cycle-related issues and fertility concerns. Understood as a supplement to medical diagnostics, it is a sensible component on the path to individualized treatment.