Endometriosis, in which the tissues that should only line the uterus also proliferates in other areas of the pelvic region, can cause great pain as well as infertility. What should everyone know about this condition?

What is endometriosis?

Endometriosis means that endometrial tissues — which normally line the uterus, where they play an important role in the menstrual cycle and fertility — are also present outside the uterus. While endometrial lesions are usually located within the pelvic region, where they may rage within the fallopian tubes, ovaries, bowels, bladder, and the abdominal wall, they have been found within the lungs and nasal mucosa as well in rarer cases. Extrauterine endometrial implants grow and subside with the menstrual cycle just like the lining of the uterus, but unlike those, they have no easy path out of the body through menstruation. The resulting build-up of tissues leads to inflammation, scarring, and sometimes great discomfort.

Chronic pain, which often worsens before and during menstruation, heavy menstrual bleeding, pain during sex, fatigue, and reduced fertility are the most characteristic symptoms of endometriosis, which research estimates affects around 10 percent of women of reproductive age.

The fact that these same symptoms are also associated with a multitude of other pelvic conditions, and may even incorrectly be seen as simply being part and parcel of the female experience during the reproductive years, explains why it takes some women years to get the proper diagnosis. Some research even suggests that women often suffer from endometriosis for a whole decade before being diagnosed!

Not all women with endometriosis experience obvious symptoms, however, and some do not find out they have endometriosis until they seek help after not being able to get pregnant. The true prevalence of the disorder may, in other words, be much higher than we think. 

Common endometriosis symptoms

Symptoms of endometriosis commonly include:

The American College of Obstetricians and Gynecologists (ACOG) notes that many women initially turn to their primary care providers because they are suffering from pelvic pain and painful, heavy, or prolonged periods. Your family doctor may not be well-equipped to diagnose you, though, as research shows that most primary care physicians are not all that familiar with the symptoms and diagnosis of the condition. This means diagnosis may require some persistence and second-opinion seeking on your part. 

What causes endometriosis?

Endometriosis is estrogen-dependent, which means it grows under the influence of this female hormone, and many women with endometriosis have estrogen dominance. This explains why the condition typically affects women of reproductive age rather than prepubescent girls and postmenopausal women, as well as why many women with endometriosis who get pregnant notice that their symptoms improve while they are expecting.

The exact causes of the condition currently remain unknown, though three main — and well-established — theories exist to explain the development of endometriosis. These are:

  • Retrograde menstruation (Sampson's theory). The tissue that lines the uterus, the endometrium, grows over the course of a menstrual cycle, at the end of which it is shed through the vagina during a period if pregnancy hasn't occurred. Retrograde menstruation is a phenomenon in which a portion of menstrual fluids instead flows backward, into the fallopian tubes and beyond. Although 90 percent of women who experience periods are believed to have some amount of retrograde menstruation while a comparatively lower 10 percent of women have endometriosis, research does support the idea that endometriosis patients have higher volumes of retrograde menstruation. Further, a primate study in which researchers induce a state to mimic retrograde menstruation showed that placing endometrial tissues outside of the uterus does result in endometriosis. Sampson's theory of endometriosis is currently the theory most strongly supported by scientific evidence. 
  • The coelomic metaplasia theory (Meyer's theory). This theory, in short, proposes that other kinds of cells can transform into endometrial cells. The fact that endometriosis is sometimes present even in prepubescent girls supports the idea that retrograde menstruation certainly isn't always to blame for the condition. 
  • Halban's theory, meanwhile, suggests that endometriosis is spread through the vascular and lymphatic systems. This theory may explain why endometriosis is rarely found outside of the pelvic region. 

More up-to-date research further suggests that endometriosis shares some characteristics with autoimmune diseases. It is possible that immune system impairments explain why extrauterine endometrial implants aren't destroyed by the body. 

The currently available theories don't offer a comprehensive or certain explanation for the development of endometriosis, but in addition to these theories, the known risk factors can offer interesting insights

Endometriosis: What are the known risk factors and possible complications?

  • Genetics. Because women whose close female relatives — especially mothers and sisters — have endometriosis are more likely to suffer from the condition themselves, endometriosis is highly likely to have a genetic component.
  • Being nulliparous. Women who have not given birth to any children have a higher risk of developing endometriosis. 
  • Early menarche. Starting your period early, before age 11, is also associated with a higher incidence of the condition, because your risk goes up with your total number of menstrual periods.
  • Being underweight. Women with a low body mass index have higher rates of endometriosis. 
  • Environmental exposure to pesticides. Women who have been exposed to the now-banned pesticides mirex and beta HCH are known to have an increased risk of developing endometriosis. Exposure usually occurs through fish or dairy consumption. 
  • Alcohol. Even moderate drinking may increase your risk of developing endometriosis. 

In addition, research has uncovered a significant overlap between endometriosis and several autoimmune diseases — women with lupus, rheumatoid arthritis, autoimmune thyroid disorders, celiac disease, and irritable bowel syndrome have been found to be more likely to have endometriosis. There is likewise an overlap between endometriosis and the chronic pain disorder fibromyalgia

Research also shows that women with endometriosis likewise have a higher risk of:

The "jury" is still out on whether endometriosis is also associated with a higher risk of melanoma skin cancer, breast, endometrial, and cervical cancer, and non-Hodgkins lymphoma, in that some studies show an increased risk while others do not. 

How is endometriosis diagnosed?

The diagnostic process may include:

  • A chat about your symptoms. 
  • A pelvic exam, during your doctor feels for ovarian cysts (often associated with endometriosis) and scarring. 
  • Imaging tests such as ultrasound or an MRI scan. 
  • An anti-mullerian hormone (AMH) test to gain insights into your ovarian reserves. 

Laparoscopy and endometrial biopsy (during which a tissue sample is taken and then researched) are, however, the only ways to definitively diagnose endometriosis. 

Once endometriosis has been diagnosed, you will further be assigned a stage — the condition comes in four stages; minimal (Stage 1), mild (Stage 2), moderate (Stage 3), and severe (Stage 4). The stage you are diagnosed with depends on the number and extent of your endometriosis implants, as well as whether you have ovarian cysts. It is important to note that the stages of endometriosis do not necessarily indicate how severe your symptoms will be. 

Endometriosis: What are your treatment options?

While there is no cure for endometriosis, the condition can be managed, often to the point where your symptoms barely impact your life. Less invasive treatments will almost always be explored first — in the form of painkillers and hormone therapy. Several surgical options are also available to women with more severe endometriosis or more severe pain.  


Non-steroidal anti-inflammatory drugs (NSAIDs), which fight inflammation and pain at the same time, are the most commonly recommended painkillers for women with endometriosis. They include ibuprofen (Motrin, Advil) and naproxen (Aleve, Naprosyn), which are available over the counter. It is important to be aware that the regular use of NSAIDs can cause side effects, including stomach ulcers, headaches, nausea, and that they have an adverse effect on your liver and kidneys. 

Hormone therapies

Because endometriosis is an estrogen-dependent condition, hormone treatments that reduce the amount of estrogen circulating within your body can slow the growth of endometriosis lesions and prevent the formation of new ones.

These hormone therapies usually prevent ovulation and are not suitable for women who are currently trying to get pregnant. The options include:

  • Combined hormonal contraceptives. These include the combined birth control pill (which contains both estrogen and progestin), the vaginal ring, and the birth control patch. The pill will make your periods lighter and more regular, and will reduce your pain. When taken continuously without a break, it can rid you of periods altogether. Combined hormonal contraceptives can be taken over the longer term. 
  • Progestin-only contraceptives. These include the birth control injection (Depo Provera), the Mirena intrauterine system, the Nexplanon birth control implant, and progestin-only birth control pills. As with combined hormonal contraceptives, you can use these for long periods of time. While all should shrink existing endometriosis lesions, some can also stop you from having periods while you take them.
  • Gonadotropin-releasing hormone (GnRH) agonists are often prescribed to stop the further proliferation of endometriosis, shrink existing implants, and prevent menstruation — all of which will help you find pain relief. They are prescribed for a maximum of six months at a time as taking them for longer induces bone density loss, but many women find their symptom relief outlasts the period of time during which they use the medication. Gonadotropin-releasing hormone agonists induce a temporary menopause-like state, which both means you cannot get pregnant while taking them as well as that you are likely to experience typical menopause symptoms such as hot flashes and night sweats. 
  • Elagolix (Orilissa) is a GnRH antagonist that was specifically FDA-approved to treat moderate and severe endometriosis pain.
  • Danazol (Danocrine) is an anti-estrogen and androgen that used to be commonly prescribed for endometriosis. Because it induces side effects like a deepening voice, more oily skin, and increased body hair (associated with male puberty), and because women should not get pregnant while on danazol, as it can harm a fetus, the drug is now prescribed less often. 
  • Another class of medications called aromatase inhibitors is also currently being researched as a possible way to manage pain in women with endometriosis. They have been found to work well in offering pain relief but their use is still off-label. 

Surgical options

Surgery can remove endometriosis implants and greatly reduce patients' symptoms, but it is important to note that undergoing surgery does not mean that your endometriosis will not return. The resulting scar tissue may also form the basis for new endometrial lesions. 

  • Laparoscopy is a less invasive way to operate compared to traditional open surgery, and will be used wherever possible. Your surgeon makes small incisions in your abdomen, through which a viewing device and surgical tools or laser are then inserted. During laparoscopic surgery for endometriosis, your surgeon will attempt to remove endometriosis implants without damaging the surrounding tissues, and can also sever adhesions. Most women will experience a reduction in pain after this procedure, though the pain can return, along with the endometriosis. Laparoscopic surgery for endometriosis can also increase your chances of getting pregnant.
  • Open surgery can be carried out to remove endometrial lesions as well. 
  • In more severe cases in which no other treatments have helped, you may discuss the possibility of a hysterectomy (in which the uterus is removed) with your healthcare provider. In some cases, the ovaries and fallopian tubes are also taken out at the same time, which induces surgical menopause. This operation is called a salpingo-oophorectomy. Both are last-resort choices.

Fertility treatments

Though laparoscopic surgery can improve your chances of getting pregnant if you have struggled to conceive, intrauterine insemination in combination with ovulation-inducing drugs (often Clomid) and IVF are two other options that greatly increase your chances of conceiving. The option your healthcare provider will suggest depends on your age, your partner's fertility, and the severity of your endometriosis.

Lifestyle changes

Heating pads or hot baths can help you find some relief from painful periods, along with a TENS machine. Patients may also find that staying away from highly processed foods, which increase inflammation, while committing to a healthy diet rich in vegetables and dietary fiber, reduces their symptoms. Supplements like turmeric, berberine, and ginger can also play a role in finding relief — but don't discount regular exercise, which reduces your estrogen levels and your pain by giving you endorphins, either. 

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