What is Endometriosis? Understanding This Chronic Condition

Endometriosis is a chronic condition where tissue similar to the lining of the uterus grows outside the uterus, causing pain, inflammation, and sometimes infertility. Learn more about its causes, symptoms, diagnosis, and treatment options.

Published: October 27, 2023•Updated: October 27, 2023

What is Endometriosis?

Endometriosis is a common, chronic condition that affects many women and girls of reproductive age. It's a disease where tissue similar to the lining of your uterus (called the endometrium) grows outside of your uterus. This 'ectopic' tissue can be found on your ovaries, fallopian tubes, and the tissues lining your pelvis. Less commonly, it can appear in other parts of the body.

Because this tissue is similar to the uterine lining, it responds to your monthly hormonal changes. This means it can thicken, break down, and bleed, just like your normal period. However, because this tissue is outside the uterus, the blood and tissue have no way to exit your body. This leads to inflammation, pain, scarring (fibrosis), and the formation of adhesions (where tissues or organs stick together).

You might hear it referred to as 'Endo' or 'Endometriotic disease'.

How Common is Endometriosis?

Endometriosis is quite common, affecting approximately 10% (about 1 in 10) of women and girls globally during their reproductive years. This means around 190 million individuals worldwide live with this condition. It can start as early as your first menstrual period (menarche) and typically lasts until menopause.

It's important to note that the true number of people affected might be even higher, as a definitive diagnosis often requires surgery, and many individuals may have mild symptoms or symptoms that are mistaken for other conditions.

Who is at Risk for Endometriosis?

While anyone of reproductive age can develop endometriosis, certain factors can increase your risk. These include:

Factors You Can't Change (Non-Modifiable)

Family History: If your mother, sister, or daughter has endometriosis, your risk is significantly higher.
Early Menarche: Starting your period before age 11.
Late Menopause: Experiencing menopause at an older age.
Short Menstrual Cycles: Cycles shorter than 27 days.
Heavy Menstrual Bleeding (Menorrhagia).
Nulliparity: Never having given birth.
Uterine Abnormalities: Certain structural issues with the uterus that obstruct menstrual flow.

Factors That Might Offer Some Protection

Having multiple pregnancies.
Starting menstruation at a later age.
Regular exercise (though evidence is mixed).
Using combined oral contraceptives.

Some lifestyle factors like diet and alcohol consumption have been studied, but the evidence linking them directly to causing or preventing endometriosis is generally considered weak or conflicting.

What Causes Endometriosis?

The exact cause of endometriosis is still unknown, and it's likely a combination of several factors working together. Researchers believe it involves a mix of genetic, hormonal, immune system, and environmental influences.

Major Theories Include:

Retrograde Menstruation: This is the most widely accepted theory. It suggests that during your period, some menstrual blood containing endometrial cells flows backward through the fallopian tubes and into the pelvic cavity, where these cells then implant and grow. However, many women experience retrograde menstruation, but not all develop endometriosis, indicating other factors are involved.
Cellular Metaplasia: This theory proposes that cells outside the uterus can transform into endometrial-like cells under certain conditions.
Immune System Dysfunction: It's thought that a faulty immune system might not recognize and destroy the misplaced endometrial tissue.
Other theories involve the spread of cells through blood vessels or the lymphatic system, or the transformation of embryonic cells.

What are the Symptoms of Endometriosis?

The symptoms of endometriosis can vary greatly from person to person, and importantly, the severity of your symptoms doesn't always match the extent of the disease. Some individuals with minimal endometriosis experience debilitating pain, while others with severe disease might have few or no symptoms.

Common Symptoms:

Severe, Painful Menstrual Cramps (Dysmenorrhea): Pain often starts before your period and can last for several days into it.
Chronic Pelvic Pain: Ongoing pain in your lower abdomen or back that isn't just during your period, lasting for at least six months.
Pain During or After Sexual Intercourse (Dyspareunia): Especially deep pain.
Difficulty Conceiving (Infertility/Subfertility).
Heavy Menstrual Bleeding (Menorrhagia) or bleeding between periods.

Less Common Symptoms:

Painful bowel movements (Dyschezia), especially during menstruation.
Painful urination (Dysuria), especially during menstruation.
Cyclical bowel or bladder symptoms like bloating, constipation, diarrhea, or blood in stool/urine that coincides with your menstrual cycle.
Fatigue, nausea, and general bloating.

Rare or Atypical Symptoms:

Coughing up blood during your period (thoracic endometriosis).
Cyclical leg pain or sciatica.
Cyclical bleeding from your belly button.

When to Seek Immediate Medical Attention (Red Flag Symptoms):

If you experience any of the following, please seek urgent medical care:

Acute, severe abdominal pain that comes on suddenly. This could indicate a ruptured ovarian endometrioma (a type of cyst) or twisting of the ovary.
Symptoms of bowel obstruction, such as severe bloating, inability to pass stool or gas, or severe flank pain.

How is Endometriosis Diagnosed?

Diagnosing endometriosis can be a journey, as symptoms can overlap with other conditions. It often involves a combination of your medical history, a physical exam, and specific investigations.

1. Your Medical History:

Your doctor will ask detailed questions about your menstrual cycles, the nature and timing of your pain, sexual health, fertility concerns, bowel and bladder habits, and any family history of endometriosis. They will also want to understand how your symptoms affect your daily life.

2. Physical Examination:

This typically includes an abdominal exam to check for tenderness or masses, and a pelvic exam. During a pelvic exam, your doctor might look for tenderness, nodules (small lumps) behind the uterus, a uterus that is fixed or tilted backward, or enlarged ovaries.

3. Investigations:

Imaging:
- Transvaginal Ultrasound (TVS): This is often the first imaging test. It's good at identifying ovarian endometriomas (sometimes called 'chocolate cysts') and can sometimes suggest deeper forms of endometriosis. However, it may appear normal in cases of superficial endometriosis.
- Magnetic Resonance Imaging (MRI): An MRI provides more detailed images and is particularly useful for assessing the extent of deep infiltrating endometriosis, especially if it involves the bowel or bladder, and for planning surgery.
Laboratory Tests: There are currently no specific blood tests that can definitively diagnose endometriosis. While a blood marker called CA-125 may be elevated in some cases, it is not specific to endometriosis and is not recommended for diagnosis.

4. Diagnostic Criteria (The Gold Standard):

The only definitive way to diagnose endometriosis is through a surgical procedure called laparoscopy, where a small incision is made, and a camera is inserted to visualize the pelvic organs. During this procedure, a biopsy (tissue sample) is taken from any suspicious lesions and examined under a microscope to confirm the presence of endometrial-like glands and stroma.

Important Note on Diagnosis:

While laparoscopy with biopsy is the gold standard, some guidelines, like those from the National Institute for Health and Care Excellence (NICE) in the UK, suggest that a diagnosis can be suspected clinically based on your symptoms and examination. In such cases, your doctor might recommend starting empirical (trial) treatment without immediate surgery, especially if your symptoms are typical. Laparoscopy is then reserved for when initial treatments don't work, imaging shows abnormalities, or when surgery is needed for treatment.

Conditions with Similar Symptoms (Differential Diagnosis):

Because endometriosis symptoms can mimic other conditions, your doctor will consider other possibilities, such as:

Pelvic Inflammatory Disease (PID)
Irritable Bowel Syndrome (IBS)
Adenomyosis (a related condition where endometrial-like tissue grows into the muscular wall of the uterus)
Uterine Fibroids
Ovarian Cysts
Interstitial Cystitis (Painful Bladder Syndrome)

How is Endometriosis Treated?

There is currently no cure for endometriosis, but various treatments can help manage symptoms, slow disease progression, and improve quality of life or fertility. Your treatment plan will be personalized based on your symptoms, age, desire for future pregnancy, and personal preferences.

1. Watchful Waiting:

For individuals with very mild or no symptoms, a 'wait and see' approach might be an option.

2. Medical Treatment (Primarily for Pain Management and Disease Suppression):

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs): Medications like ibuprofen or naproxen can help manage pain.
Hormonal Contraceptives: Combined oral contraceptives (the pill), patches, or vaginal rings are often used continuously to suppress menstruation and reduce pain.
Progestins: These include progestin-only pills, injections (like Depo-Provera), or a levonorgestrel-releasing intrauterine system (IUS, like Mirena). They work by suppressing the growth of endometrial-like tissue.
GnRH Agonists: Medications like leuprolide or goserelin induce a temporary, reversible 'medical menopause' by significantly reducing estrogen levels. To manage side effects like bone density loss, they are often used with 'add-back' therapy (low-dose estrogen/progestin).
GnRH Antagonists: Newer oral medications (e.g., elagolix, relugolix) that also suppress estrogen production.

3. Surgical Treatment:

Conservative Surgery (Laparoscopy): This involves using minimally invasive surgery to remove or destroy endometriotic implants and adhesions while preserving the uterus and ovaries. It aims to reduce pain and improve fertility.
Definitive Surgery (Hysterectomy with or without Oophorectomy): This involves removing the uterus (hysterectomy), and sometimes the fallopian tubes and ovaries (bilateral salpingo-oophorectomy). This is typically considered for severe symptoms when fertility is no longer desired and other treatments have failed. If ovaries are removed in premenopausal women, hormone replacement therapy (HRT) is usually needed.

4. Lifestyle and Complementary Therapies:

While evidence for many lifestyle interventions is still emerging or weak, some individuals report benefit from:

Pelvic floor physical therapy to address muscle pain.
Anti-inflammatory diets.
Regular, moderate exercise.
Acupuncture.
Stress management techniques.

When to Consider Referral to a Specialist:

You might be referred to a specialist center with multidisciplinary expertise if:

Your diagnosis is uncertain.
Initial medical treatments haven't worked.
You have severe, complex, or deeply infiltrating endometriosis (e.g., involving the bowel, bladder, or ureters).
You are seeking management for associated infertility.

What are the Complications of Endometriosis?

Endometriosis can lead to various complications, both in the short and long term.

Short-Term Complications:

Ovarian Endometrioma Rupture or Torsion: An endometrioma (a cyst on the ovary) can rupture or twist, causing sudden, severe abdominal pain that requires emergency surgery.
Adhesion Formation: Scar tissue can form, binding organs together and causing pain or organ dysfunction.

Long-Term Complications:

Infertility/Subfertility: This is a significant concern, affecting 30-50% of women with endometriosis. It can be due to distorted pelvic anatomy, inflammation affecting egg/sperm/embryo function, or changes in the uterus's ability to accept an embryo.
Chronic Pelvic Pain: Pain can persist even after visible endometriosis is treated, sometimes becoming a centralized pain syndrome.
Organ Damage: Deeply infiltrating endometriosis can damage organs like the bowel, bladder, and ureters, potentially leading to blockages or loss of function.
Increased Cancer Risk: There is a small but statistically significant increased risk of certain types of epithelial ovarian cancer (specifically endometrioid and clear cell types). However, the absolute risk remains low.

Pregnancy-Related Complications:

Emerging evidence suggests a possible association between endometriosis and a slightly increased risk of certain pregnancy complications, including:

Preterm birth
Placenta previa (where the placenta covers the cervix)
Small for gestational age (SGA) infants
Preeclampsia
Cesarean delivery

It's important to remember that the absolute risk increase is generally small, and research in this area is ongoing.

Can Endometriosis Be Prevented?

Unfortunately, there is currently no known way to prevent the onset of endometriosis.

However, once diagnosed, the focus shifts to 'secondary prevention' – managing the condition to prevent its progression, reduce symptoms, and minimize long-term complications. For example, continuous use of hormonal contraceptives after surgery may help delay or prevent the recurrence of pain and endometriomas.

There are no screening programs for endometriosis; diagnosis is typically pursued based on symptoms.

What is the Prognosis for Endometriosis?

Endometriosis is a chronic condition with a variable and unpredictable course. The lesions can grow, remain stable, or sometimes even shrink on their own.

Expected Outcomes:

With appropriate and individualized management, many individuals can achieve good control of their pain symptoms and significantly improve their quality of life. For those experiencing infertility, various treatments, including surgery and assisted reproductive technologies like IVF, can improve the chances of conception.

Recurrence:

It's common for symptoms and/or lesions to recur, even after successful treatment. For instance, pain can return in 40-50% of individuals within five years after conservative surgery.

Long-Term Outlook:

Living with endometriosis often requires a long-term management strategy, similar to other chronic conditions like diabetes or asthma. This often involves a multidisciplinary approach, including gynecologists, pain specialists, physical therapists, and mental health professionals, to provide comprehensive care.

When to See a Doctor

If you are experiencing severe or persistent pelvic pain, painful periods that interfere with your daily life, pain during sex, difficulty getting pregnant, or any of the red flag symptoms mentioned above, please consult with a healthcare professional. Early diagnosis and management can significantly improve your quality of life.

Frequently Asked Questions

What is the difference between endometriosis and adenomyosis?

Endometriosis is a condition where tissue similar to the lining of the uterus grows outside the uterus. Adenomyosis is a distinct condition that can cause similar symptoms, and healthcare professionals consider it when evaluating pelvic pain, as mentioned in the differential diagnosis for endometriosis.

Can endometriosis turn into cancer?

While the absolute risk is low, there is a small but statistically significant increased risk of certain types of ovarian cancer (specifically endometrioid and clear cell types) in individuals with endometriosis. It's important to discuss any concerns with your doctor.

Will I be able to get pregnant if I have endometriosis?

Endometriosis can cause infertility or subfertility, affecting 30-50% of women with the condition. However, many individuals with endometriosis can still conceive, sometimes with the help of treatments like surgery or assisted reproductive technologies (e.g., IVF).

Does pregnancy cure endometriosis?

Pregnancy does not cure endometriosis. While symptoms may improve during pregnancy due to hormonal changes, the condition is chronic and symptoms often return after childbirth.

Will a hysterectomy cure my endometriosis?

Hysterectomy (removal of the uterus) is considered a definitive surgery for severe symptoms, especially if the ovaries are also removed (oophorectomy). While it can significantly reduce symptoms, endometriosis can sometimes recur, particularly if ovarian tissue remains or if implants were outside the removed organs.

What are the side effects of hormonal treatments like GnRH agonists?

GnRH agonists induce a temporary 'medical menopause' by reducing estrogen levels. Side effects can include hot flashes, night sweats, vaginal dryness, and potential bone density loss. 'Add-back' therapy (low-dose estrogen/progestin) is often used to manage these side effects.

Is surgery the only way to diagnose endometriosis?

Laparoscopy with histological confirmation (biopsy) is the gold standard for a definitive diagnosis. However, a clinical diagnosis based on symptoms and examination is often made, and empirical medical treatment may be started without immediate surgery, especially if symptoms are typical.

What is the difference between ablation and excision surgery?

The provided dossier mentions 'excision or ablation/fulguration' as methods to remove or destroy endometriotic implants during conservative surgery. Excision involves cutting out the lesions, while ablation/fulguration involves destroying them, typically with heat or laser.

How long is the recovery time after laparoscopic surgery for endometriosis?

The provided dossier does not specify typical recovery times for laparoscopic surgery for endometriosis. Recovery can vary based on the extent of surgery and individual factors.

Can endometriosis come back after surgery?

Yes, recurrence of symptoms and/or lesions is common even after surgery. Pain recurrence can be as high as 40-50% within 5 years after conservative surgery, and endometriomas can also recur.

Are there any specific foods I should eat or avoid?

The evidence for specific dietary changes to prevent or treat endometriosis is generally considered weak or emerging. Some patients report benefit from an anti-inflammatory diet, but there are no universally recommended specific foods to eat or avoid based on strong evidence.

Can endometriosis cause bladder or bowel problems?

Yes, endometriosis can cause cyclical bowel symptoms (like bloating, constipation, diarrhea, or blood in stool) and bladder symptoms (like painful urination or blood in urine), especially during menstruation. Deeply infiltrating endometriosis can also damage these organs, potentially leading to obstruction.

Why is there such a long delay in getting a diagnosis?

The dossier highlights that true prevalence is difficult to determine as definitive diagnosis requires surgery, and many individuals may be asymptomatic or have symptoms attributed to other conditions. This can contribute to diagnostic delays.

Can teenagers get endometriosis?

Yes, endometriosis primarily affects individuals of reproductive age, and symptoms can begin at the first menstrual period (menarche), meaning teenagers can indeed develop the condition.

Does endometriosis go away after menopause?

Symptoms of endometriosis often, but not always, improve after menopause due to the natural decline in estrogen levels. However, the condition is chronic and may persist in some cases.

What is 'silent endometriosis'?

The dossier notes that the severity of symptoms does not correlate well with the extent (stage) of the disease. This means some individuals with severe endometriosis may be asymptomatic, which could be referred to as 'silent endometriosis'.

Can endometriosis affect my mental health?

While the dossier does not explicitly detail mental health impacts, living with chronic pain and a long-term condition like endometriosis can significantly affect quality of life, which often includes mental well-being. Long-term management often involves a multidisciplinary approach, which can include mental health professionals.

What is the difference between Stage 1 and Stage 4 endometriosis?

The dossier mentions that the severity of symptoms does not correlate well with the extent (stage) of the disease, noting that a person with minimal (Stage I) disease may have debilitating pain, while someone with severe (Stage IV) disease may be asymptomatic. However, it does not provide specific definitions for the different stages.

Does the stage of endometriosis correlate with my pain level?

No, the dossier explicitly states that the severity of symptoms does not correlate well with the extent (stage) of the disease. A person with minimal (Stage I) disease may have debilitating pain, while someone with severe (Stage IV) disease may be asymptomatic.

Are there non-hormonal treatments for endometriosis pain?

Yes, nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen are first-line medical treatments used to manage endometriosis pain. Additionally, some patients explore lifestyle and complementary therapies like physical therapy, dietary changes, exercise, and acupuncture, though evidence for these is often weak or emerging.

What is an endometrioma or 'chocolate cyst'?

An endometrioma is a type of ovarian cyst that forms when endometrial-like tissue grows on the ovary. They are sometimes called 'chocolate cysts' due to their dark, thick, old blood content. Transvaginal ultrasound is often used to identify them.

Can endometriosis grow in other parts of my body, like my lungs?

Yes, while less common, endometrial cells can travel through the blood vessels or lymphatic system to other parts of the body, explaining distant implants. The dossier mentions cyclical hemoptysis (coughing up blood) as an atypical symptom, which can occur with thoracic endometriosis (in the lungs).

Should I have my ovaries removed during a hysterectomy for endometriosis?

Definitive surgery for endometriosis may involve hysterectomy (removal of the uterus) often with bilateral salpingo-oophorectomy (removal of fallopian tubes and ovaries). This is considered for severe symptoms when fertility is not desired. If ovaries are removed in premenopausal women, hormone replacement therapy (HRT) is typically required.

What is 'add-back' therapy?

'Add-back' therapy involves taking low-dose estrogen and/or progestin alongside GnRH agonists. This is done to manage the side effects of GnRH agonists, such as bone density loss and menopausal symptoms, which occur due to the significant reduction in estrogen levels.

Is IVF my only option for pregnancy with endometriosis?

No, IVF is not necessarily the only option. For those with infertility due to endometriosis, treatments can include conservative surgery to remove implants and adhesions, as well as assisted reproductive technologies like IVF. The best approach depends on individual circumstances and disease severity.