The endometrium is the layer of tissue that covers the inside of the uterus, which breaks apart and causes bleeding during a woman’s menstrual cycle. Endometriosis is a condition that occurs when cells similar to those in the endometrium grow in locations other than the uterus. Endometrial cells can also grow on the fallopian tubes, ovaries, and other tissues near the uterus. Endometriosis can also affect other areas of the body in rare cases. The most obvious symptom of endometriosis is pain feels like intense menstrual cramps.

Pelvic pain and infertility are the most common symptoms of endometriosis. However, a 2010 study published in the Journal of Assisted Reproduction and Genetics (JARG) reports that 20 to 25 percent of women with endometriosis are asymptomatic.

The pain caused by endometriosis can range a mild to severe and may be a cramping or stabbing pain. The degree of pain has some correlation with the extent of the endometriosis, but it’s often less severe in advanced cases. The reason for this counterintuitive result is that advanced cases of endometriosis often have significant scarring that’s less sensitive to pain. Pelvic pain from endometriosis is usually strongest during menstruation, although it can also occur at other times.

About 40 percent of women with endometriosis are infertile, according to the 2010 JARG study. The specific cause of infertility primarily depends on the disease’s stage, which is usually due to an inflammatory response that impairs conception in the early stages of endometriosis. In later stages, infertility is more likely to be caused by adhesions and distortions in pelvic anatomy.

Endometriosis doesn’t have a specific cause, as its development depends on multiple factors that aren’t mutually exclusive. The Mayo Clinic reports that the most likely causes of endometriosis include the following:

• Retrograde menstruation
• Peritoneal cell transformation
• Embryonic cell transformation
• Immune system disorders
• Surgical scars
• Endometrial cell transformation

Retrograde menstruation occurs when menstrual fluid flows back into the pelvic cavity rather than out of the body. The endometrial cells in this fluid can adhere to various surfaces, allowing them to continue growing. These cells can then break apart and bleed during the menstrual cycle.

Peritoneal cells that line the inner side of the abdomen can change due to hormones and immune factors, causing them to take on the properties of endometrial cells.

Hormones like estrogen can also change embryonic cells in their early stages of development during puberty. These changes can make embryonic cells act like endometrial cells.

Endometrial cells may attach to an incision during surgeries such as a C-section or hysterectomy.

These cells can also move to other parts of the body via some means, typically the circulatory or lymphatic system.

Some immune system disorders can prevent the body from recognizing when endometrial-like tissue is growing outside the uterus, allowing this condition to continue.

The risk factors for endometriosis may be categorized into genetic and environmental factors.

Endometriosis has a strong genetic component, so the daughters and sisters of women with endometriosis have a six times greater chance of developing it themselves. A propensity towards low progesterone is also a genetic factor for endometriosis due to the resulting hormone imbalance.

The environmental risk factors for endometriosis include prolonged exposure to estrogen, especially when a woman’s menarche or late menopause. Any obstruction to the menstrual flow such as Müllerian anomalies is also a risk factor.

A healthcare practitioner often discovers the first signs of endometriosis during a routine physical examination. Surgery remains the gold standard for diagnosing this condition, as the benefits of non-invasive techniques are currently inconclusive.

Laparoscopy is typically used to diagnose endometriosis. This surgical procedure involves placing a camera in the abdominal cavity to observe the extent and severity of the lesions. Direct observation may be possible if the lesions are in the vagina. The practitioner may also take a biopsy at this time.

An ultrasound of the pelvic region may identify large endometriotic cysts known as endometriomoas. Vaginal ultrasound also has clinical value in visualizing endometriomas prior to surgery, typically in cases with a high suspicion of endometriosis.

Magnetic resonance imaging (MRI) can detect small, deep endometriotic lesions. However, this diagnostic technique is uncommon due to its cost and limited availability.

WebMD reports that the chances of developing endometriosis can’t be completely eliminated. However, a number of practices may be able to reduce your risk, including exercise, lowering estrogen, and avoiding alcohol.

Exercise is an effective way to reduce your chances of endometriosis, especially if it reduces your body weight and body fat. Exercise can also increase the levels of beneficial estrogen metabolites and reduce the levels of harmful ones, thus lowering your risk of endometriosis. Aerobic exercise that increases your heart rate and burns calories is therefore the most beneficial in preventing endometriosis. Aim for a minimum of 30 minutes of aerobic activity at least four times a week.

Estrogen increases the formation of endometrial tissue, so reducing its production can lower your risk of endometriosis. Various forms of hormone therapy can reduce your estrogen level, including birth control pills, patches, and vaginal rings. However, these therapies will only be effective as long as you take them. As with any hormone therapy, you should discuss the pros and cons with your doctor before taking it.

Many studies show that alcohol can increase estrogen production, which also increases your risk of endometriosis. Limit your alcoholic intake to one drink per day if you’re trying to minimize your risk of endometriosis.

Managing endometriosis requires a multi-pronged approach due to its complex nature. The disease’s stage when diagnosed is one of the most important factors to consider when selecting the best therapy to take. Current treatments have a high probability of relieving pain, but preserving fertility is more challenging in advanced cases. A recurrence of endometriosis is most likely after pseudo-menopause or surgery.

For more information, please visit our complete Endometriosis Guide.