Endometriosis

Symptoms that raise suspicion

• Very painful periods that do not respond to usual painkillers (dysmenorrhea)
• Pelvic pain that also occurs outside your period
• Deep pain during or after sex
• Pain with bowel movements or urination, especially during menstruation
• Heavy or irregular menstrual bleeding
• Severe tiredness, especially during your period
• Cyclical abdominal bloating and changes in bowel habits
• Difficulty getting pregnant

You don't need to have all the symptoms. If you have two or three that affect your life, it is worth looking into.

What is endometriosis

Endometriosis is a chronic, inflammatory, hormone-dependent disease in which tissue similar to the endometrium (the lining of the inside of the uterus) grows outside the uterus: on the peritoneum, the ovaries, the uterine ligaments, the septum between the vagina and the rectum, the bowel or the bladder.

This tissue responds to the hormones of the cycle just like the endometrium: it grows and bleeds. But because it is outside the uterus, this blood cannot leave the body and causes inflammation that repeats month after month. Over time, this inflammation can create adhesions and fibrosis, so that some organs become stuck together and lose mobility. It also promotes the growth of new nerve endings in the lesions, one of the reasons they hurt.

It affects about 10% of women of reproductive age. It is not just a painful period taken to the extreme: it is a disease that can distort pelvic anatomy and affect fertility and quality of life.

Types of endometriosis

• Superficial peritoneal endometriosis: implants on the surface of the peritoneum. It can cause a lot of pain even though it barely shows up on imaging tests.
• Ovarian endometrioma: a cyst in the ovary containing old blood (the so-called “chocolate cyst”). It is the easiest form to detect on ultrasound.
• Deep endometriosis: lesions that infiltrate more than 5 mm below the peritoneum, typically in the uterosacral ligaments, the rectovaginal septum, the bowel, the ureter or the bladder. It is the form usually associated with the most pain and the one that requires the most experience to diagnose and operate on.
• Adenomyosis: often coexists with endometriosis, although it is a different condition. It has its own page.

Important: the extent of the disease does not match the intensity of the pain. There are patients with minimal lesions and disabling pain, and patients with extensive endometriosis that is found almost by chance. This is not a contradiction: pain also depends on the sensitization of the nervous system and on the muscular component, not just on the lesion. In our research at Hospital Clínic, more than half of patients with deep endometriosis had symptoms of central sensitization.

Why it is diagnosed so late

The diagnostic delay in endometriosis is still several years. The reasons are well known and, to a large extent, avoidable:

• The cultural normalization of period pain: “every woman goes through it,” “that's just how it is.”
• The relief provided by hormonal birth control: it is an effective treatment, but it is sometimes prescribed without investigating the cause of the pain.
• The belief that a normal ultrasound rules out endometriosis: superficial endometriosis often goes unnoticed on ultrasound, and deep endometriosis is only detected if the person performing the scan is specifically looking for it.
• Digestive or urinary symptoms that steer the workup toward other specialties.

How it is diagnosed

Expert transvaginal ultrasound

It is the first diagnostic test and, in expert hands, the one that provides the most information. An ultrasound focused on endometriosis is not a routine gynecological ultrasound: it follows a systematic international consensus protocol (IDEA) and assesses the mobility of the uterus and ovaries, how the organs slide over each other (sliding sign), the uterosacral ligaments, the posterior compartment, the rectal wall and the bladder, as well as looking for signs of adenomyosis.

MRI

It is reserved for planning complex surgery or when involvement of the bowel, ureter or bladder is suspected and a complete map is needed before surgery.

Laparoscopy

It is no longer used to diagnose endometriosis. It is an invasive procedure with its own risks, and today the diagnosis is made with the medical history, the examination and an expert ultrasound. Laparoscopy is reserved for treating a disease that has already been diagnosed.

Treatment

There is no single treatment: the decision depends on your symptoms, your age, whether you want to get pregnant and the treatments you have already tried. These are the available options:

Medical treatment

The goal is to stop the hormonal stimulus that feeds the disease and, ideally, to suppress periods in order to interrupt the monthly cycle of inflammation. The options are continuous combined hormonal contraception (with no break), progestogens, the levonorgestrel intrauterine system (LNG-IUS) and, in selected cases, GnRH agonists or oral GnRH antagonists. When well chosen and well tolerated, medical treatment controls symptoms in a large proportion of patients.

Pain treatment

It is essential and yet often forgotten. It includes pelvic floor physical therapy, since many patients with endometriosis develop secondary myofascial pain that can persist even when the disease is under control (in our study, almost half of the patients had it); pain-modulating medications when there is a neuropathic component; and pain neuroscience education.

Surgery

It is indicated when medical treatment does not work or is not tolerated, when other organs are affected, or in some situations related to fertility. Surgery for deep endometriosis should be performed by an experienced multidisciplinary team, because it may require colorectal or urological surgery in the same procedure. A well-planned first surgery performed at an expert center avoids repeat operations.

Fertility

Endometriosis can make it harder to get pregnant, but many women with endometriosis do get pregnant. If you want to have a baby, it is best to plan for it from the start, because it determines which treatment is chosen and in what order.

What to expect at the first visit

A detailed medical history, an examination including the pelvic floor, an expert ultrasound at the same visit if possible, and a clear explanation of your diagnosis and treatment options. If you have previous reports or test results, bring them: they change the starting point.

Frequently asked questions about endometriosis

References

1. Becker CM, Bokor A, Heikinheimo O, et al. ESHRE guideline: endometriosis. Hum Reprod Open. 2022;2022(2):hoac009. doi:10.1093/hropen/hoac009 · PubMed
2. As-Sanie S, Mackenzie SC, Morrison L, et al. Endometriosis: a review. JAMA. 2025;334(1):64-78. doi:10.1001/jama.2025.2975 · PubMed
3. Guerriero S, Condous G, van den Bosch T, et al. Systematic approach to sonographic evaluation of the pelvis in women with suspected endometriosis, including terms, definitions and measurements: a consensus opinion from the International Deep Endometriosis Analysis (IDEA) group. Ultrasound Obstet Gynecol. 2016;48(3):318-32. doi:10.1002/uog.15955 · PubMed
4. Vercellini P, et al. Update on medical treatment of endometriosis: new drugs or new therapeutic approaches? Gynecol Obstet Invest. 2024. doi:10.1159/000542947 · PubMed
5. Quintas-Marquès L, Martínez-Zamora MÁ, Camacho M, et al. Central sensitization in patients with deep endometriosis. Pain Med. 2023;24(8):1005-7. doi:10.1093/pm/pnad002 · PubMed
6. Quintas-Marquès L, Valdés-Bango M, Box C, et al. Multidimensional evaluation of myofascial pelvic pain and other comorbidities in endometriosis patients. J Clin Med. 2025;14(10):3455. doi:10.3390/jcm14103455 · PubMed

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