Endometriosis: symptoms, causes, stages, diagnosis and treatment

Endometriosis is a chronic gynaecological condition in which tissue similar to the lining of the uterus grows outside the uterus. It commonly affects the ovaries, fallopian tubes and tissues around the pelvis, but it can sometimes occur elsewhere in the body.

For some women, endometriosis causes severe period pain and significantly affects everyday life. For others, symptoms may be mild or absent, and the condition may only be discovered during an evaluation for infertility or another procedure.

The World Health Organization (WHO) estimates that endometriosis affects about 10% of women of reproductive age worldwide, equivalent to approximately 190 million people. It can occur from the time periods begin through menopause.

Importantly, the amount of endometriosis does not always match the amount of pain. Someone with relatively limited disease may experience severe pain, while another person with more extensive disease may have few symptoms.

What happens when a woman has endometriosis?

Endometriosis involves the growth of endometrial-like tissue outside the uterus. This tissue responds to hormonal changes during the menstrual cycle.

It can become inflamed and bleed, but because the blood and tissue are outside the uterus, they cannot leave the body in the same way as menstrual blood. Repeated inflammation can contribute to scar tissue and adhesions.

Over time, endometriosis may lead to:

• Pelvic or abdominal pain
• Very painful periods
• Lower back pain
• Pain during or after sexual intercourse
• Pain during bowel movements or urination
• Heavy menstrual bleeding or spotting
• Bloating, constipation or diarrhea
• Ovarian cysts called endometriomas
• Adhesions and scar tissue
• Difficulty becoming pregnant

Endometriosis can therefore affect much more than menstruation. It may interfere with work, sleep, relationships, sexual health, physical activity and emotional wellbeing.

What does life with endometriosis look like?

Life with endometriosis can vary considerably from one woman to another.

Some women experience severe pain for several days around every menstrual period. Others may have persistent pelvic or lower back pain. Some experience pain during sex or bowel movements, while others mainly struggle with heavy periods, fatigue or infertility.

The unpredictability can itself become difficult. A woman may feel well for several days and then experience debilitating pain around her period. Symptoms can also affect concentration, sleep, exercise and social activities.

However, an endometriosis diagnosis does not mean that someone has to live with uncontrolled pain permanently. Treatment can help manage symptoms, and treatment plans can be adjusted according to symptoms, fertility plans, age, disease characteristics and personal preferences.

What are the early signs of endometriosis?

Early signs may be subtle and are sometimes mistaken for “normal” period problems.

Possible early warning signs include:

• Period pain that is unusually severe
• Pain that interferes with school, work or normal activities
• Pain that progressively becomes worse over time
• Persistent pelvic pain
• Lower back pain associated with menstruation
• Pain during or after sex
• Pain when passing stool during periods
• Pain while urinating during periods
• Heavy menstrual bleeding
• Bleeding or spotting between periods
• Difficulty becoming pregnant
• Recurrent bloating, constipation or diarrhoea around menstruation

Severe menstrual pain should not automatically be dismissed as something a woman simply has to tolerate.

What are three signs of endometriosis?

Three particularly important signs are:

1. Severe or worsening period pain
2. Chronic pelvic or lower abdominal pain
3. Pain during sex, bowel movements or urination, particularly around menstruation

Other symptoms such as heavy bleeding, infertility, bloating and lower back pain may also occur.

What are the warning signs of endometriosis?

Warning signs become more concerning when menstrual symptoms consistently interfere with everyday life.

You should consider speaking with a gynaecologist if period pain causes you to miss work or school, requires repeated pain medication, prevents normal physical activity, or is accompanied by pain during sex, bowel movements or urination.

Persistent pelvic pain or unexplained difficulty becoming pregnant also deserves medical evaluation.

What is the cause of endometriosis?

The exact cause of endometriosis is not known.

Several mechanisms have been proposed, including retrograde menstruation, genetic factors, immune-system changes and hormonal influences. However, endometriosis is considered a complex disease, and no single explanation accounts for every case.

What is the root cause of endometriosis?

There is currently no scientifically established single “root cause” of endometriosis.

Retrograde menstruation, in which menstrual blood flows backwards through the fallopian tubes into the pelvis, is one proposed mechanism. But retrograde menstruation can occur in people who do not develop endometriosis, so it is unlikely to be the complete explanation.

Genetic susceptibility, immune responses and hormonal factors may also contribute.

What causes a person to get endometriosis?

A person may develop endometriosis because of a combination of genetic, hormonal, immune and reproductive factors. Having a close biological relative with endometriosis can increase risk.

Other factors associated with increased risk include shorter menstrual cycles, longer or heavier periods and certain problems affecting menstrual flow.

Can stress cause endometriosis?

Stress is not established as a direct cause of endometriosis.

However, living with chronic pain can increase stress, anxiety and emotional distress. Stress may also influence how a person experiences and copes with chronic pain.

This means managing stress, getting adequate sleep and seeking emotional support can be useful parts of overall care, but they should not be presented as a cure or as the underlying cause of endometriosis.

At what age does endometriosis start?

Endometriosis can occur after menstruation begins, including during the teenage years. It is often diagnosed during the reproductive years.

The condition is commonly identified in women in their 20s, 30s and 40s, although symptoms can begin much earlier.

What is the peak age for endometriosis?

There is no single age at which every woman develops endometriosis. It can occur throughout the reproductive years.

Although it is commonly diagnosed in the 20s, 30s and 40s, symptoms may have started years before diagnosis. This is one reason why endometriosis can remain undiagnosed for a long time. WHO notes that delays in diagnosis remain common.

Can a woman suddenly develop endometriosis?

Endometriosis generally does not appear overnight. However, symptoms can seem to start suddenly or become noticeably worse over a relatively short period.

A woman may have had small or silent lesions for some time before pain, heavy bleeding, bowel symptoms or fertility difficulties become apparent.

Is PCOS also called endometriosis?

No. PCOS and endometriosis are two different conditions.

Polycystic ovary syndrome (PCOS) is primarily associated with hormonal and ovulatory abnormalities and may cause irregular periods, excess androgen-related symptoms and difficulties with ovulation.

Endometriosis involves endometrial-like tissue growing outside the uterus and is commonly associated with pelvic pain, painful periods and sometimes infertility.

A person can have PCOS, endometriosis or both.

What are the four stages of endometriosis?

Endometriosis is commonly classified using the American Society for Reproductive Medicine (ASRM) system into four stages:

• Stage I – minimal: Small, superficial lesions with limited disease.
• Stage II – mild: More lesions and somewhat deeper involvement.
• Stage III – moderate: Deeper lesions, ovarian involvement and adhesions may occur.
• Stage IV – severe: Extensive disease, larger endometriomas and significant adhesions may be present.

An important point is that stage does not reliably predict pain. A woman with Stage I disease can have severe pain, while another woman with Stage IV disease may have relatively few symptoms.

Therefore, treatment should not be based on the stage alone.

What can be mistaken for endometriosis?

Several conditions can cause symptoms similar to endometriosis, including:

• Adenomyosis
• Uterine fibroids
• Ovarian cysts
• Pelvic inflammatory disease
• Irritable bowel syndrome
• Urinary tract conditions
• Painful periods without an underlying pelvic disease
• Pelvic floor disorders
• Other causes of chronic pelvic pain

This is why a proper medical history, examination and appropriate imaging are important.

Can you feel endometriosis with your finger?

Usually, no.

Endometriosis lesions are generally located inside the pelvis or abdomen and cannot simply be felt with a finger. A pelvic examination may sometimes detect tenderness, an ovarian cyst or other abnormalities, but small endometriosis lesions may not be detectable during an examination.

Trying to diagnose endometriosis by self-examination is therefore not reliable.

How do I confirm if I have endometriosis?

Diagnosis usually begins with a detailed discussion about:

• Menstrual cycle and period pain
• Pelvic or abdominal pain
• Pain during sex
• Bowel or bladder symptoms
• Bleeding patterns
• Previous surgeries
• Fertility concerns
• Family history

A gynaecologist may then perform a pelvic examination and recommend imaging.

Can a gynecologist see endometriosis?

A gynaecologist can assess symptoms and perform a pelvic examination. Ultrasound and MRI can also identify certain forms of endometriosis, particularly ovarian endometriomas and some forms of deep endometriosis.

However, small or superficial lesions may not be visible on routine imaging.

Importantly, updated clinical guidance increasingly supports using symptoms, examination and imaging to make a presumptive or clinical diagnosis and begin appropriate treatment rather than automatically requiring surgery before treatment. ACOG’s 2026 guidance specifically addresses clinical findings and imaging in the diagnosis of endometriosis.

How to 100% diagnose endometriosis?

There is no simple blood test that can currently provide a 100% diagnosis.

Historically, laparoscopy with direct visualisation of lesions, sometimes combined with tissue examination, has been considered the definitive diagnostic approach. However, modern guidance recognises that surgery is not always necessary before starting treatment when the clinical picture and imaging strongly suggest endometriosis.

The appropriate diagnostic approach depends on the individual patient.

Is endometriosis very serious?

Endometriosis is a chronic condition that can be serious, particularly when it causes severe pain, infertility, extensive adhesions or involvement of the bowel, bladder or other organs.

At the same time, endometriosis is not automatically an emergency or life-threatening disease. Many women can manage their symptoms effectively with appropriate treatment.

The key is not to ignore persistent or severe symptoms.

How painful is endometriosis on a scale of 1 to 10?

There is no universal pain score for endometriosis.

Some women describe their pain as mild, while others describe it as extremely severe. A numerical score such as 8/10 or 9/10 can help a doctor understand the intensity, but the number does not determine the stage of disease.

There is also no reliable relationship between pain intensity and the amount of visible endometriosis.

Is endometriotic cyst harmful?

An endometriotic cyst, also called an endometrioma or “chocolate cyst,” develops when endometriosis affects the ovary.

Endometriomas can cause pelvic pain and may be associated with fertility problems. Their size, symptoms, appearance and effect on ovarian function all matter when deciding whether monitoring, medication or surgery is appropriate.

Not every endometrioma requires immediate surgery.

Can endometriosis be cancerous?

Endometriosis itself is considered a benign condition, not cancer.

However, some research has identified associations between endometriosis and certain ovarian cancers. This does not mean that endometriosis normally turns into cancer.

An ovarian cyst or pelvic mass that appears unusual should always be evaluated appropriately by a doctor.

What is the best treatment for endometriosis?

There is no single “best treatment” for every woman.

Treatment depends on symptoms, age, extent of disease, fertility plans, previous treatment and personal preferences.

Treatment options may include:

Pain relief

Non-steroidal anti-inflammatory drugs (NSAIDs) and other pain-relieving medicines may help control pain in appropriate patients.

Hormonal treatment

Hormonal treatments can reduce or suppress menstrual cycling and may decrease endometriosis-associated pain.

Options may include combined hormonal contraceptives, progestins and GnRH-based treatments. Not every option is suitable for someone trying to become pregnant.

Surgery

Laparoscopic surgery can remove or treat visible endometriosis lesions and adhesions in selected patients.

Surgery may be considered when symptoms are severe, medication is ineffective or poorly tolerated, significant endometriosis is present, or certain fertility-related circumstances make surgery appropriate.

However, surgery is not automatically the first treatment for everyone.

Fertility treatment

For women experiencing infertility, management may involve treatment of endometriosis as well as fertility approaches such as ovulation induction, intrauterine insemination (IUI) or in-vitro fertilisation (IVF), depending on individual circumstances.

Is surgery the only treatment for endometriosis?

No.

Medication, hormonal treatment, pain management, physiotherapy and other supportive approaches may be used depending on the individual’s symptoms.

Surgery has an important role in selected cases, but it is not the only treatment. Endometriosis can also recur after surgery, which is why long-term management may be necessary.

What is the newest treatment for endometriosis?

There is no single treatment that can accurately be called the newest or best treatment for everyone.

Recent advances have included newer hormonal approaches, particularly medicines that act on the gonadotropin-releasing hormone (GnRH) pathway, alongside improved imaging, earlier clinical diagnosis and more individualised treatment.

The important development is not simply a new drug but a broader approach to endometriosis care: earlier recognition, appropriate imaging, personalised medical treatment, fertility planning and surgery when indicated.

Treatment should be selected by a gynaecologist based on the patient’s specific circumstances.

Can endometriosis be cured?

At present, there is no definitive cure for endometriosis. Treatment aims to control pain and other symptoms, improve quality of life, address fertility concerns where relevant and reduce the impact of the disease. Symptoms can sometimes return after treatment.

This does not mean that symptoms cannot be controlled. Many patients experience significant improvement with an appropriate treatment plan.

Frequently asked questions about endometriosis

What does endometriosis feel like?

It may feel like severe menstrual cramps, deep pelvic pain, lower back pain or abdominal pain. Some women experience pain during sex, bowel movements or urination. Others mainly experience heavy bleeding, bloating, fatigue or fertility problems.

Can endometriosis cause infertility?

Yes. Endometriosis can interfere with fertility through inflammation, adhesions, ovarian involvement and changes affecting the reproductive organs. However, having endometriosis does not mean that pregnancy is impossible.

Can endometriosis affect the bowel?

Yes. Endometriosis can involve tissues around the bowel and may cause pain during bowel movements, abdominal pain, bloating, constipation or diarrhoea, particularly around menstruation.

Can endometriosis affect the bladder?

Yes. In some cases, endometriosis can involve the bladder or tissues around it and cause pain during urination or, rarely, blood in the urine.

What is the most painful stage of endometriosis?

Stage IV is classified as the most extensive stage, but it is not necessarily the most painful. Pain severity does not reliably correspond to the stage or amount of disease.

Does endometriosis go away after menopause?

Symptoms often improve after menopause because ovarian hormone levels decline, but endometriosis-related symptoms do not necessarily disappear in every person. Persistent symptoms after menopause should be medically evaluated.

When should I see a gynecologist?

Consider seeing a gynaecologist if you have severe period pain, persistent pelvic pain, pain during sex, bowel or bladder pain associated with menstruation, unusually heavy bleeding, an ovarian cyst or unexplained difficulty becoming pregnant.

Early evaluation can help identify the cause of symptoms and prevent years of unnecessary suffering.

The bottom line

Endometriosis is more than “painful periods.” It is a chronic condition that can affect the pelvis, bowel, bladder, fertility, sexual health and quality of life.

The exact cause remains unknown, and there is no single treatment suitable for everyone. Importantly, pain severity does not necessarily indicate disease stage, and surgery is not always required before treatment can begin.

If symptoms suggest endometriosis, a gynaecologist can evaluate the medical history, perform an examination and use appropriate imaging such as ultrasound or MRI. In selected cases, laparoscopy may be required for direct visualisation and treatment.

Recognising the warning signs early is important. Severe period pain that repeatedly interferes with everyday life should not simply be accepted as normal.

For women in Kolkata experiencing persistent pelvic pain, painful periods, heavy bleeding, fertility concerns or symptoms suggestive of endometriosis, appropriate gynaecological evaluation and pelvic imaging can be an important first step.

To consult a Gynecologist at Sparsh Diagnostic Centre for treatment, call our helpline number 9830117733.

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Disclaimer:

No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.

Sources and further reading

• World Health Organization – Endometriosis
• Cleveland Clinic – Endometriosis
• ACOG – Endometriosis FAQ
• ACOG – Diagnosis of Endometriosis, 2026 clinical practice guideline
• Office on Women’s Health – Endometriosis
• ESHRE – Endometriosis guideline