Difference Between Endometriosis and Ovarian Cyst: Symptoms, Causes & Treatment

Endometriosis and an ovarian cyst are not the same condition. Endometriosis is a condition in which tissue similar to the lining of the uterus grows outside the uterus, while an ovarian cyst is a sac or pouch that develops in or on an ovary.

Many ovarian cysts are not related to endometriosis. Some, however, can develop because of endometriosis. These are called endometriomas or “chocolate cysts.”

Both endometriosis and ovarian cysts can cause pelvic pain, and both can sometimes affect fertility. However, many ovarian cysts cause no symptoms and may go away without treatment. Endometriosis can also cause significant pain or fertility problems even when there is no ovarian cyst.

In this guide, we will explain the difference between endometriosis and an ovarian cyst, including their symptoms, causes, ultrasound findings, fertility effects, treatment options and the role of laparoscopic surgery. We will also explain how an endometrioma differs from a regular ovarian cyst and when you should see a gynecologist.

What Is the Difference Between Endometriosis and an Ovarian Cyst?

Endometriosis is a medical condition, while an ovarian cyst is a sac or pouch that develops in or on an ovary. They can occur separately, but endometriosis can also cause a specific type of ovarian cyst called an endometrioma.

The difference becomes easier to understand when you compare them side by side:

Key takeaway

Endometriosis is a condition. An ovarian cyst is a finding. An endometrioma is an ovarian cyst associated with endometriosis.

This distinction is important because not every ovarian cyst is caused by endometriosis, and having an ovarian cyst does not automatically mean that you have endometriosis.

At the same time, a woman can have endometriosis without having an ovarian cyst at all.

What Is Endometriosis?

Endometriosis is a condition in which tissue similar to the lining of the uterus grows outside the uterus. It most commonly affects areas within the pelvis, including the ovaries, fallopian tubes and the lining of the pelvic cavity.

This tissue can respond to hormonal changes during the menstrual cycle. Repeated inflammation and bleeding can contribute to pelvic pain and the formation of scar tissue called adhesions.

Endometriosis may cause:

• Painful periods
• Long-lasting pelvic pain
• Pain during sexual intercourse
• Pain during bowel movements
• Pain during urination in some cases
• Heavy menstrual bleeding
• Difficulty becoming pregnant in some women

However, symptoms can vary significantly. Some women with endometriosis may have mild symptoms, while others may experience severe or persistent pain.

Importantly, the severity of pain does not always match the extent or stage of endometriosis. This is why symptoms, medical history and appropriate imaging need to be considered together.

Where Can Endometriosis Occur?

Endometriosis can develop in different areas of the pelvis. Common locations include:

• Ovaries
• Pelvic lining (peritoneum)
• Fallopian tubes
• Areas around the uterus
• Bowel or rectum
• Bladder
• Other pelvic tissues

When endometriosis affects an ovary, it can sometimes form an endometrioma, also known as a chocolate cyst.

Endometriosis is commonly described according to where it occurs, including superficial peritoneal endometriosis, ovarian endometriosis (endometrioma), and deep endometriosis. More than one type can be present in the same woman.

The type and location of endometriosis can be important when deciding how it should be evaluated and treated.

What Is an Ovarian Cyst?

An ovarian cyst is a sac or pouch that develops in or on an ovary. It may contain fluid, blood or other material, depending on the type of cyst.

Ovarian cysts are common, particularly during the reproductive years. Many are benign (non-cancerous) and do not cause any symptoms.

Some ovarian cysts, especially functional cysts related to the menstrual cycle, can resolve on their own without treatment. Others may persist, become larger, cause symptoms or require further evaluation.

Importantly, not every ovarian cyst is related to endometriosis. Ovarian cysts can develop for several different reasons, and an ultrasound is often used to determine their size, appearance and location.

Common Types of Ovarian Cysts

There are several types of ovarian cysts. They are not all managed in the same way.

Functional cyst: These are common cysts related to the normal menstrual cycle. Many functional cysts disappear naturally within a few weeks or menstrual cycles.

Hemorrhagic cyst: This occurs when bleeding develops within an ovarian cyst, often a functional cyst. It may cause pelvic pain and can sometimes resolve on its own.

Dermoid cyst: Also called a mature cystic teratoma, this is a type of ovarian growth that can contain tissues such as fat, hair or other material. It usually develops from germ cells.

Cystadenoma: This type develops from cells on the surface of the ovary and may contain watery or mucus-like fluid. Some can become large and may cause pressure or abdominal discomfort.

Endometrioma: This is an ovarian cyst associated with endometriosis. It can contain old blood and is commonly known as a “chocolate cyst.”

An endometrioma is an ovarian cyst associated with endometriosis.

This does not mean that every ovarian cyst is an endometrioma. The type of cyst matters when a gynecologist is deciding whether observation, further evaluation or treatment is appropriate.

For a broader explanation of how ovarian cysts differ from uterine fibroids, see our guide on Difference Between Cyst and Fibroid.

What Is an Endometrioma or Chocolate Cyst?

An endometrioma is a type of ovarian cyst associated with endometriosis. It develops when endometriosis affects an ovary.

Endometriosis involves tissue similar to the lining of the uterus growing outside the uterus. When this condition affects an ovary, repeated bleeding and inflammation can contribute to the formation of an endometrioma.

An endometrioma may contain old, thickened blood. Over time, this can give the cyst a dark brown appearance, which is why it is commonly called a “chocolate cyst.”

An endometrioma is different from a simple functional ovarian cyst. A functional cyst may develop as part of the normal menstrual cycle and often disappears on its own. An endometrioma is associated with an underlying condition—endometriosis—and may persist.

Some women with an endometrioma have pelvic pain, particularly painful periods. Others may have pain during sex or experience difficulty becoming pregnant.

However, the presence of an endometrioma does not automatically mean that surgery is required. Management depends on factors such as symptoms, cyst characteristics, fertility plans, ovarian reserve, other areas of endometriosis and previous treatment.

Is Every Ovarian Cyst an Endometrioma?

No. Every ovarian cyst is not an endometrioma.

Ovarian cysts can develop for many different reasons. Functional, hemorrhagic, dermoid and other types of ovarian cysts are different from an endometrioma.

An endometrioma specifically refers to an ovarian cyst associated with endometriosis. Ultrasound findings, symptoms and medical history can help a gynecologist determine whether a cyst may be an endometrioma or another type of ovarian cyst.

This distinction is important because “ovarian cyst” is a broad term, while “endometrioma” describes a specific type of ovarian cyst linked to endometriosis.

Endometriosis vs Ovarian Cyst: What Symptoms Are Different?

Endometriosis and ovarian cysts can cause similar symptoms, so symptoms alone cannot always tell them apart.

Pelvic pain, pain during sex and changes in menstrual symptoms can occur with both conditions. Some women with an ovarian cyst have no symptoms at all, while endometriosis can cause significant symptoms even when an ovarian cyst is not present.

Endometriosis Symptoms

Endometriosis may cause symptoms such as:

• Very painful periods
• Chronic or recurring pelvic pain
• Pain during sexual intercourse
• Pain during bowel movements
• Pain during urination, particularly around the menstrual period
• Heavy or irregular menstrual bleeding
• Bloating
• Fatigue
• Difficulty becoming pregnant

The pattern of pain can be particularly important. For example, pelvic pain that repeatedly becomes worse around menstruation may raise suspicion for endometriosis.

However, symptoms can vary considerably between women.

Some women with endometriosis may have significant disease with relatively mild symptoms, while others may experience severe or persistent pain.

This is one reason why the severity of pain alone should not be used to determine how extensive endometriosis is.

Ovarian Cyst Symptoms

Many ovarian cysts cause no symptoms and are discovered during a routine pelvic ultrasound or examination.

When an ovarian cyst does cause symptoms, they may include:

• Pelvic pain
• One-sided lower abdominal pain
• Bloating or abdominal fullness
• Feeling full quickly
• Pain during sexual intercourse
• Changes in menstrual periods
• Frequent urination if the cyst puts pressure on the bladder
• Difficulty passing stool if it puts pressure on the bowel

The symptoms can depend on the cyst’s size, location, type and whether a complication has occurred.

A small cyst may cause no symptoms, while a larger or complicated cyst may cause discomfort or pressure.

Key Takeaway

Symptoms alone cannot reliably tell whether pelvic pain is caused by endometriosis, an ovarian cyst or another condition.

A gynecologist may consider the timing and pattern of symptoms along with the examination and ultrasound findings. This helps determine whether further evaluation for an ovarian cyst, endometriosis or another pelvic condition is needed.

Can Endometriosis Cause an Ovarian Cyst?

Yes. Endometriosis can cause a specific type of ovarian cyst called an endometrioma.

An endometrioma develops when endometriosis affects the ovary. It can contain old blood that has accumulated over time, giving it the characteristic dark appearance associated with the term “chocolate cyst.”

An endometrioma is different from many common functional ovarian cysts, which are related to the menstrual cycle and may disappear naturally.

Endometriomas can be associated with pelvic pain, painful periods and fertility concerns, although not every woman with an endometrioma will have the same symptoms.

The presence of an endometrioma also does not automatically mean that surgery is necessary. A gynecologist considers the cyst’s appearance and size, symptoms, fertility plans, ovarian reserve, other endometriosis findings and potential benefits and risks of treatment before recommending management.

In simple terms: Endometriosis can lead to an ovarian cyst, but that specific cyst is called an endometrioma. Not every ovarian cyst is caused by endometriosis.

Endometrioma vs Simple Ovarian Cyst

A simple or functional ovarian cyst and an endometrioma are different types of ovarian cysts. A functional cyst is often related to normal ovarian function, while an endometrioma is associated with endometriosis.

The important point is that “ovarian cyst” is a broad term. It includes several different types of cysts, while an endometrioma is a specific type associated with endometriosis.

This is why “ovarian cyst” and “endometrioma” should not be used as interchangeable terms.

A cyst seen on an ultrasound should therefore be evaluated based on its type, appearance, size, symptoms and clinical context, rather than assuming that every cyst is caused by endometriosis.

Can Endometriosis Occur Without an Ovarian Cyst?

Yes. Endometriosis can occur even when there is no ovarian cyst or endometrioma.

Endometriosis does not have to involve the ovary. It can affect the pelvic lining, areas around the uterus, fallopian tubes, bowel, bladder and other pelvic tissues.

This means a woman can have symptoms associated with endometriosis even when her ovaries appear normal on an ultrasound.

A normal-looking ovary therefore does not automatically rule out endometriosis.

This is particularly important when a woman has symptoms such as severe period pain, recurring pelvic pain or pain during sex or bowel movements. The overall clinical picture matters, not just whether an ovarian cyst is visible.

Can an Ovarian Cyst Cause Endometriosis?

No. An ordinary ovarian cyst does not cause endometriosis.

Most ovarian cysts develop for reasons that are unrelated to endometriosis. They can include functional cysts, hemorrhagic cysts, dermoid cysts and other types.

Endometriosis is a separate medical condition. However, the two can occur in the same woman.

When endometriosis affects the ovary, it can lead to the formation of an endometrioma. In other words, the relationship works in this direction:

Endometriosis → can cause an endometrioma

But:

Ordinary ovarian cyst → does not cause endometriosis

This distinction is important because not every woman with an ovarian cyst has endometriosis, and not every woman with endometriosis has an ovarian cyst.

How Are Endometriosis and Ovarian Cysts Diagnosed?

Endometriosis and ovarian cysts are diagnosed using a combination of symptoms, medical history, physical examination and imaging when appropriate. There is no single symptom or test that explains every case.

Medical History and Symptoms

A gynecologist may ask about:

• Period pain and when it occurs
• Chronic or recurring pelvic pain
• Pain during sexual intercourse
• Pain during bowel movements
• Pain during urination
• Menstrual pattern and bleeding
• Previous ovarian cysts
• Difficulty becoming pregnant
• Previous pelvic surgery or treatment

The timing and pattern of symptoms can provide important clues.

For example, pain that repeatedly becomes worse around menstruation may raise suspicion for endometriosis. However, symptoms can overlap with ovarian cysts and several other pelvic conditions.

Pelvic Ultrasound

Pelvic ultrasound is commonly used to evaluate ovarian cysts and can also help identify certain forms of endometriosis.

For an ovarian cyst, ultrasound can help assess:

• Size
• Location
• Shape
• Whether it appears fluid-filled or contains solid components
• Internal features of the cyst
• Blood flow and other characteristics when Doppler assessment is used

For suspected endometriosis, ultrasound may help identify:

• Ovarian endometriomas
• Certain features of deep endometriosis
• Adhesions or changes in pelvic anatomy
• Other pelvic abnormalities

A transvaginal ultrasound is particularly useful when evaluating the pelvis in appropriate patients.

However, an ultrasound does not always detect every form of endometriosis. A normal ultrasound therefore does not necessarily mean that endometriosis is impossible.

MRI When Needed

MRI may be recommended in selected patients when more detailed pelvic imaging is needed.

It can provide a more detailed view of pelvic anatomy and may be useful when deep endometriosis is suspected or when treatment planning requires additional information.

MRI is not required for every woman with pelvic pain or every ovarian cyst. The decision depends on the individual clinical situation.

Is Laparoscopy Needed to Diagnose Endometriosis?

No. Diagnostic laparoscopy is not automatically required for every patient suspected of having endometriosis.

Modern endometriosis care places an important role on the combination of symptoms, clinical assessment and appropriate imaging. Laparoscopy may still be considered in selected situations, particularly when symptoms persist, imaging is inconclusive or surgical treatment is being considered.

Therefore, the decision to perform laparoscopy should be individualized rather than treated as a mandatory test for every suspected case of endometriosis.

Can Endometriosis and Ovarian Cysts Affect Fertility?

Yes, both can sometimes be associated with fertility problems, but neither automatically means infertility.

The effect on fertility depends on the underlying condition, the type of ovarian cyst, the woman’s age, ovarian function and other reproductive factors.

Endometriosis and Fertility

Endometriosis can affect fertility in some women.

Inflammation and changes in the pelvic anatomy may interfere with the normal movement of the egg, sperm or embryo. Endometriosis affecting the ovaries may also be associated with fertility concerns.

However, many women with endometriosis become pregnant naturally or with appropriate fertility treatment.

The presence of endometriosis therefore does not mean that pregnancy is impossible.

Ovarian Cysts and Fertility

Most common ovarian cysts do not prevent pregnancy.

The effect on fertility depends largely on the type and underlying cause of the cyst. A temporary functional cyst, for example, is very different from an endometrioma or another ovarian condition.

Endometriomas deserve particular consideration because both the disease itself and treatment involving the ovary can be relevant to future fertility.

If surgery is being considered, the doctor needs to balance the potential benefit of removing the cyst against the importance of preserving healthy ovarian tissue and ovarian reserve.

This is why fertility plans should be discussed before deciding on treatment for an endometrioma.

Does the Size of an Endometrioma Matter?

Yes, the size of an endometrioma matters, but there is no single size in mm that automatically means surgery is required.

A 30 mm (3 cm) endometrioma and a 100 mm (10 cm) endometrioma are obviously different in size, but size is only one part of the decision.

A gynecologist may consider:

• Endometrioma size
• Whether it is growing
• Pain and other symptoms
• Fertility plans
• Ovarian reserve
• Other areas of endometriosis
• Previous treatment or surgery
• Whether one or both ovaries are affected
• Ultrasound or MRI findings
• Potential benefits and risks of surgery

Therefore, it is not medically accurate to say that “an endometrioma above X mm always needs surgery.”

The right approach is to evaluate the whole clinical picture.

Is a 30 mm (3 cm) Endometrioma Dangerous?

A 30 mm (3 cm) endometrioma is not automatically dangerous or an automatic reason for surgery.

Its significance depends on symptoms, ultrasound findings, fertility plans, ovarian reserve and whether other endometriosis is present.

If it is causing significant symptoms or there are other concerning findings, a gynecologist may recommend further evaluation or treatment. In other situations, monitoring may be appropriate.

Is a 50 mm (5 cm) Endometrioma Dangerous?

A 50 mm (5 cm) endometrioma is not automatically dangerous simply because it measures 50 mm (5 cm).

A larger endometrioma may require closer assessment, particularly if it is causing pain, increasing in size or affecting fertility.

However, size alone should not be used as a universal surgery threshold. The potential benefit of surgery needs to be balanced against the risk of affecting healthy ovarian tissue and ovarian reserve.

Does a Large Endometrioma Need Surgery?

Not every large endometrioma automatically needs surgery.

Surgery may be considered when there are significant symptoms, certain concerning imaging findings, complications, fertility-related considerations or other clinical reasons.

The decision should be individualized.

When ovarian endometrioma surgery is performed, preserving as much healthy ovarian tissue as possible is an important consideration because ovarian surgery can affect ovarian reserve.

How Are Ovarian Cysts Treated?

Treatment for an ovarian cyst depends on its type, size, appearance, symptoms, age and other individual factors.

A cyst that appears benign and is not causing significant problems may not require immediate treatment.

Observation

Observation may be appropriate for selected ovarian cysts.

This is particularly common when a cyst appears benign, symptoms are mild or absent, and the cyst is expected to resolve naturally.

The doctor may recommend a follow-up ultrasound to see whether the cyst changes or disappears.

Medication

Medication does not treat every type of ovarian cyst.

Treatment depends on the type of cyst and the underlying condition. In some situations, hormonal treatment may be used to manage related menstrual or endometriosis symptoms, but it does not mean that every ovarian cyst can be treated with medicine.

The treatment plan should therefore be based on the diagnosis rather than simply the presence of a cyst.

Laparoscopic Ovarian Cystectomy

Laparoscopic ovarian cystectomy is a minimally invasive procedure used to remove an ovarian cyst in selected patients.

The surgeon makes small abdominal incisions and uses specialized instruments to access the pelvis and remove the cyst.

When appropriate, the aim is to treat the cyst while preserving as much healthy ovarian tissue as possible.

Whether cystectomy is suitable depends on the cyst’s type, size, appearance, symptoms and the patient’s individual circumstances.

When Is More Extensive Surgery Considered?

More extensive surgery may be considered when the cyst has concerning features or when other clinical factors make a larger procedure necessary.

The decision can depend on the woman’s age, symptoms, cyst characteristics, ovarian status and whether there is concern about malignancy.

A suspicious ovarian mass should be evaluated carefully rather than treated in the same way as a typical functional cyst.

How Is Endometriosis Treated?

Endometriosis treatment depends on symptoms, disease characteristics, fertility goals and the individual patient’s circumstances.

There is no single treatment that is appropriate for every woman with endometriosis.

Pain Management

Pain management aims to reduce endometriosis-related symptoms and improve quality of life.

Depending on the patient, this may involve pain-relieving medicines and other supportive approaches.

The treatment should also consider the underlying cause of persistent pelvic pain rather than relying only on temporary pain relief.

Hormonal Treatment

Hormonal treatment can help control endometriosis-related pain and symptoms in appropriate patients. Hormonal medicines can reduce or suppress the hormonal stimulation of endometriosis and may help reduce symptoms.

The choice of treatment depends on factors such as symptoms, side effects, medical history and whether the woman is currently trying to become pregnant.

Laparoscopic Surgery

Laparoscopic surgery may be used to treat endometriosis in selected patients.

Depending on where the disease is located, surgery may involve removing or treating endometriosis lesions using appropriate surgical techniques.

Ovarian endometriomas require particular care. When surgery is considered, the surgeon must balance treatment of the endometrioma with preservation of healthy ovarian tissue and ovarian reserve.

Surgery is therefore not automatically required simply because endometriosis or an endometrioma is present.

Endometriosis and Fertility Treatment

Fertility treatment for women with endometriosis depends on the individual reproductive situation.

Factors that may influence the treatment plan include:

• Age
• Duration of infertility
• Ovarian reserve
• Extent and location of endometriosis
• Previous treatment or surgery
• Other fertility factors
• Pregnancy goals

A woman trying to conceive may need a different treatment approach from someone whose primary concern is pain control.

For this reason, fertility goals should be discussed early when planning endometriosis treatment.

Is Laparoscopic Surgery Used for Endometriosis and Ovarian Cysts?

Yes, laparoscopy can be used for selected patients with endometriosis, endometriomas and certain ovarian cysts.

Laparoscopy is a minimally invasive surgical technique that uses small abdominal incisions and a camera to examine and treat structures inside the pelvis.

Depending on the diagnosis, it may allow the surgeon to:

• Remove selected ovarian cysts
• Treat an ovarian endometrioma
• Remove or treat endometriosis lesions
• Assess pelvic structures directly
• Treat certain adhesions or other abnormalities

However, laparoscopy is not always required.

The decision depends on the diagnosis, symptoms, imaging findings, fertility plans and expected benefits and risks of surgery.

Ovarian surgery requires particular care because removing or damaging healthy ovarian tissue can affect ovarian reserve. This is especially important when treating an endometrioma in a woman who may want to become pregnant in the future.

Endometriosis vs Ovarian Cyst: Which Is More Serious?

Neither endometriosis nor an ovarian cyst is automatically more serious than the other.

A simple functional ovarian cyst may disappear without treatment and may never cause symptoms. In contrast, endometriosis is a chronic condition that can cause ongoing pelvic pain and may affect fertility in some women.

An endometrioma is different from a typical functional ovarian cyst because it is associated with endometriosis.

At the same time, certain ovarian cyst complications can require urgent medical attention.

The seriousness of either condition depends on the type, symptoms, size, location, imaging findings, complications and individual circumstances.

So rather than asking only, “Which is more dangerous?”, it is more useful to ask:

What exactly is the diagnosis, what symptoms are present, and what does the imaging show?

When Should You See a Gynecologist?

You should consider seeing a gynecologist if pelvic pain is severe, persistent, recurring or affecting your daily life.

A gynecological evaluation is particularly important if you have:

• Severe period pain
• Persistent or recurring pelvic pain
• Pain during sexual intercourse
• Pain during bowel movements, especially around periods
• Repeated ovarian cysts
• An ovarian cyst that persists on follow-up
• Difficulty becoming pregnant
• An ultrasound showing an endometrioma
• Increasing or unexplained pelvic symptoms

The earlier evaluation can help identify whether the symptoms are related to endometriosis, an ovarian cyst or another condition.

Severe period pain is not something you always have to “just live with.”

If period pain regularly interferes with work, sleep, exercise, relationships or daily activities, it deserves proper medical evaluation.

When Is Pelvic Pain an Emergency?

Sudden or severe pelvic pain can sometimes be a medical emergency and should not be ignored.

Seek urgent medical attention if you experience:

• Sudden, severe pelvic or abdominal pain
• Severe pain accompanied by vomiting
• Fainting or severe dizziness
• Heavy vaginal bleeding
• Fever with severe pelvic pain
• Sudden or rapidly worsening symptoms

These symptoms can sometimes occur with complications such as ovarian torsion or ovarian cyst rupture, although there can be other causes of sudden pelvic pain as well.

Not every episode of endometriosis pain is an emergency. However, new, sudden or unusually severe pain should be assessed promptly, particularly when it is accompanied by vomiting, fainting, fever or heavy bleeding.

A Gynecologist’s Perspective: Endometriosis vs Ovarian Cyst

Expert Perspective by Dr. Nidhi Mishra

Obstetrician and Gynaecologist, World Laparoscopy Hospital

When a patient has pelvic pain and an ultrasound shows an ovarian cyst, it is important not to assume that the cyst explains every symptom.

The first step is to understand the patient’s symptoms and their pattern. We then look carefully at the ultrasound findings and try to determine what type of cyst is present.

An ovarian cyst does not automatically mean endometriosis. At the same time, endometriosis can be present even when there is no ovarian endometrioma.

When an endometrioma is identified, treatment decisions should consider more than just its size. Symptoms, other areas of endometriosis, fertility plans, ovarian reserve and the potential benefits and risks of surgery all need to be considered.

A useful way to approach these cases is:

Symptoms → Ultrasound → Cyst Type → Endometriosis Features → Fertility Plans → Ovarian Reserve → Treatment

The goal is not simply to remove a cyst. The goal is to choose the right treatment while considering the patient’s symptoms, reproductive goals and long-term ovarian health.

Note: This expert perspective should be reviewed and approved by Dr. Nidhi Mishra before publication. The wording should not be presented as her exact quotation unless she has approved it.

Endometriosis vs Ovarian Cyst: A Simple Decision Guide

When you are trying to understand an ultrasound report or ongoing pelvic symptoms, think through these steps:

SYMPTOMS

Painful periods + recurring pelvic pain

→ Consider evaluation for endometriosis.

ULTRASOUND

An ovarian cyst is seen

→ Determine its size, appearance, location and likely type.

LOCATION

Endometriosis-like changes are seen outside the ovary

→ Further evaluation may be needed to understand the location and extent of disease.

CYST TYPE

Ovarian cyst with features suggestive of endometriosis

→ Consider an endometrioma.

ENDOMETRIOSIS FEATURES

Endometriosis symptoms are present but there is no ovarian cyst

→ Endometriosis can still be present.

FERTILITY

Endometrioma + plans for pregnancy

→ Discuss fertility goals and ovarian reserve before deciding whether surgery is appropriate.

MANAGEMENT

Treatment should be based on the complete clinical picture

→ Symptoms + imaging + diagnosis + fertility goals + risks should guide the next step.

URGENT SYMPTOMS

Sudden severe pelvic pain, particularly with vomiting, fainting, fever or heavy bleeding

→ Seek urgent medical assessment.

The key message is simple:

Do not judge an ovarian cyst or endometrioma by size alone. Understand what it is, where it is, what symptoms it is causing and how it fits into your overall health and fertility plans.

Conclusion

Endometriosis and an ovarian cyst are not the same condition. Endometriosis is a condition in which tissue similar to the lining of the uterus grows outside the uterus, while an ovarian cyst is a sac or pouch that develops in or on an ovary.

An endometrioma is a specific type of ovarian cyst associated with endometriosis. However, not every ovarian cyst is an endometrioma, and endometriosis can occur without an ovarian cyst.

Both conditions can sometimes cause pelvic pain and fertility concerns, but their causes and treatment can be very different. Treatment depends on the diagnosis, symptoms, imaging findings, fertility plans and other individual factors.

Importantly, surgery is not automatically required because an ovarian cyst or endometrioma is present. If you have severe period pain, persistent pelvic pain or an ovarian cyst on your ultrasound, a gynecologist can help determine the cause and the most appropriate next step.

Frequently Asked Questions About Endometriosis and Ovarian Cysts

What is the difference between endometriosis and an ovarian cyst?

Endometriosis is a condition in which tissue similar to the lining of the uterus grows outside the uterus, while an ovarian cyst is a sac or pouch that develops in or on an ovary. They are not the same condition, although they can occur together. Endometriosis can also cause a specific type of ovarian cyst called an endometrioma.

Can endometriosis cause an ovarian cyst?

Yes, endometriosis can cause a specific type of ovarian cyst called an endometrioma. It develops when endometriosis affects the ovary and may contain old blood. Endometriomas are also commonly called “chocolate cysts.”

Is an endometrioma the same as an ovarian cyst?

An endometrioma is a type of ovarian cyst, but not every ovarian cyst is an endometrioma. An endometrioma is specifically associated with endometriosis and may contain old blood. Other ovarian cysts can develop for completely different reasons, including normal changes during the menstrual cycle.

Can an ovarian cyst cause endometriosis?

No, an ordinary ovarian cyst does not cause endometriosis. Most ovarian cysts are unrelated to endometriosis. However, endometriosis can affect the ovary and lead to the formation of an endometrioma.

Can you have endometriosis without an ovarian cyst?

Yes, you can have endometriosis without having an ovarian cyst or endometrioma. Endometriosis can affect the pelvic lining, fallopian tubes, areas around the uterus, bowel, bladder and other pelvic tissues. Therefore, a normal-looking ovary does not automatically rule out endometriosis.

What does an endometrioma look like on ultrasound?

An endometrioma can have characteristic ultrasound features, often appearing as a cyst with relatively uniform, low-level internal echoes sometimes described as a “ground-glass” appearance. However, ultrasound findings need to be interpreted by a trained clinician in the context of symptoms and other pelvic findings. Not every cyst with internal echoes is an endometrioma.

Is a 30 mm (3 cm) endometrioma dangerous?

A 30 mm (3 cm) endometrioma is not automatically dangerous or an automatic reason for surgery. Its significance depends on symptoms, ultrasound findings, fertility plans, ovarian reserve and other features of endometriosis. Your gynecologist may recommend monitoring or treatment depending on the overall situation.

Is a 50 mm (5 cm) endometrioma dangerous?

A 50 mm (5 cm) endometrioma is not automatically dangerous simply because it measures 50 mm (5 cm). A larger endometrioma may require careful evaluation, particularly if it causes symptoms or is changing over time. Surgery is not decided by size alone because treatment also needs to consider fertility and ovarian reserve.

Can endometriosis and ovarian cysts affect fertility?

Yes, endometriosis and some types of ovarian cysts can be associated with fertility problems, but neither automatically means infertility. Endometriosis may affect fertility through inflammation and changes in pelvic anatomy, while most common functional ovarian cysts do not prevent pregnancy. Endometriomas require particular consideration because both the condition and ovarian surgery can be relevant to ovarian reserve.

Can an endometrioma go away on its own?

An endometrioma does not usually behave like a typical functional ovarian cyst that disappears naturally within a few menstrual cycles. It may persist and can sometimes change in size over time. Whether it should simply be monitored or treated depends on symptoms, imaging findings, fertility plans and other individual factors.

Does an endometrioma need surgery?

No, an endometrioma does not automatically need surgery. Surgery may be considered in selected patients based on symptoms, cyst characteristics, fertility considerations and other clinical factors. When ovarian surgery is performed, preserving healthy ovarian tissue and minimizing the potential impact on ovarian reserve are important considerations.

Can endometriosis or an ovarian cyst be treated with laparoscopy?

Yes, laparoscopy can be used to treat selected cases of endometriosis, endometriomas and certain ovarian cysts. It is a minimally invasive surgical approach that allows the surgeon to access and treat pelvic structures through small incisions. However, laparoscopy is not required for every patient, and the decision depends on the diagnosis, symptoms, imaging findings and treatment goals.