Endometriosis vs. PCOS: What Are the Differences?

Endometriosis and polycystic ovary syndrome (PCOS) are gynecologic conditions that affect female reproductive organs. Although PCOS only affects the ovaries, endometriosis can affect the ovaries, the uterus, and other organs, including the bladder and intestines.

One in 10 people with a uterus have been diagnosed with endometriosis and 4% to 20% have been diagnosed with PCOS worldwide. Both conditions can lead to infertility and other health conditions.

This article discusses the differences between PCOS and endometriosis.

Woman laying on the couch in pain from endometriosis

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How to Know If It's Endometriosis or PCOS

Although endometriosis and PCOS share symptoms, they are different conditions. Endometriosis causes chronic pelvic pain, while PCOS is a metabolic disorder.

What Is Endometriosis?

The innermost lining of the uterus is called the endometrium. The endometrium helps keep the uterus functioning properly, especially during pregnancy. When the endometrial tissue begins to grow outside the uterus, it's called endometriosis.

What Is PCOS?

The ovaries have several important functions, including the release of reproductive hormones. The growth and release of an egg from the ovary (ovulation) depend on those reproductive hormones. PCOS occurs when the ovaries and adrenal glands produce too much androgen hormone, called hyperandrogenism. Conversely, overproduction of androgen is responsible for PCOS. In addition, cysts (fluid-filled sacs) form in the ovaries of most people with PCOS.

Symptoms

Symptoms that endometriosis and PCOS have in common are irregular menstrual periods and infertility. However, several dissimilarities set them apart.

Endometriosis Symptoms:

PCOS Symptoms:

  • Hirsutism (excess hair growth on the face, chest, and abdomen)
  • Obesity
  • Severe acne
  • Insulin resistance
  • Acanthosis nigricans (patches of thick, velvety, darkened skin)
  • Fluid-filled sacs in the ovaries
  • Male-pattern baldness

Endometriosis vs. PCOS

Endometriosis
  • Pelvic pain

  • Heavy periods

  • Constipation

  • Infertility

PCOS
  • Obesity

  • Diabetic

  • Masculine features

  • Infertility

Causes and Risk Factors

Although hormonal imbalances play a part in endometriosis and PCOS, other causes and risk factors are unique to each condition.

Endometriosis

Endometriosis is the most common cause of pelvic pain in people of childbearing age. Endometrial tissue that spreads beyond the uterus can swell and bleed as it does in the uterus each month. Scar tissue, adhesions, and blockages of other organs are side effects of endometriosis.

It's unclear what causes endometriosis, but possibilities include retrograde menstruation (menstrual blood flowing in the wrong direction), genetics, impaired immune system, increased estrogen levels, and abdominal surgery (endometrial tissue can be transferred to other organs during surgery).

Endometriosis risk factors include:

  • Early menarche (before age 11)
  • Family history of endometriosis (mother or daughter)
  • Short monthly periods (27-day cycle or less)
  • Heavy menstrual bleeding
  • Infertility
  • High estrogen levels
  • Alcohol use (increases estrogen levels)

PCOS

Although the exact reason why PCOS occurs is not fully understood, experts agree that it is a complex endocrine condition with multiple causes, including diet and lifestyle factors.

Fat cells also release androgens, which is why it's not uncommon for obese people to experience PCOS. Hyperandrogenism also leads to insulin resistance and diabetes.

Additionally, irregular menstrual cycles and multiple cysts in the ovaries lead to infertility. PCOS is one of the most common causes of female infertility, affecting 70% to 80% of people wanting a pregnancy.

Risk factors for having PCOS include:

  • Obesity
  • Diabetes
  • Epilepsy
  • Hyperandrogenism
  • Family history of PCOS
  • Premature puberty (before age 8 or 9)

Endometriosis and PCOS Link

A study found that although endometriosis and PCOS share abnormalities in hormonal balance, body weight, age of menarche (when periods start), and reproductive irregularities, the causes of those abnormalities differ. Therefore, a link between the two gynecologic disorders cannot be made.

Can You Have Both?

Although rare, people can have both endometriosis and PCOS. Such reported cases show that endometriosis is often mild when found in combination with PCOS.

Diagnosis

Endometriosis and PCOS require several tests to confirm their diagnosis. Endometriosis often takes longer to diagnose than PCOS.

The following are ways to diagnose endometriosis:

  • Pelvic exam: Identifies masses, cysts, and areas of pain.
  • Imagining tests: A pelvic ultrasound can help find cysts in the ovaries, while magnetic resonance imaging (MRI) recognizes endometriosis by taking pictures of organs and tissues.
  • Laparoscopy: A surgery that looks in your abdominal cavity to find signs of endometriosis. The surgeon may diagnose endometriosis by visualizing the invading tissue; however, a biopsy (removing a sample of tissue to be examined in a lab) may be required to confirm the diagnosis.


Your healthcare provider may give you medications that help decrease estrogen levels. If medications relieve your symptoms, you likely have endometriosis.

The following are ways to diagnose PCOS:

  • Physical exam: Identifies increased body mass index (BMI), and signs of other conditions that could be responsible for PCOS symptoms
  • Pelvic exam: Feeling for enlarged ovaries
  • Pelvic ultrasound: Helpful in finding ovarian cysts
  • Blood work: Checks for increased androgen levels, thyroid disease, diabetes, and cholesterol level


Your healthcare provider will also review a history of your menstrual cycles and fertility.

Treatment

Medications, surgery, and lifestyle changes can improve the symptoms and quality of life for people with endometriosis or PCOS.

Endometriosis

Treatment for endometriosis is often geared toward pain management. However, considering the person's desire for pregnancy is also important.

  • Medications: Nonsteroidal anti-inflammatory drugs (NSAIDs) are used first to decrease inflammation and alleviate discomfort. Hormonal medications (birth control pills and estrogen blockers) and non-hormonal medications (aromatase inhibitors) can help reduce pain and inflammation.
  • Surgery: Removal of the uterus, fallopian tubes, and ovaries may be necessary to alleviate the symptoms of endometriosis. In addition, removing endometrial tissue from other organs (bladder, colon) may also be an option. Unfortunately, it's not uncommon for endometriosis to recur (come back) after surgery.
  • Lifestyle: A study found that cooking with clean ingredients, fresh fruits, vegetables, and decreasing gluten and dairy improved endometrial symptoms. This study was supported by other research indicating a healthy lifestyle can improve both the physical and mental challenges of endometriosis.

PCOS

Treatment of PCOS is tailored to decrease the symptoms and reduce the long-term health implications caused by it, which include diabetes and cardiovascular disease. The following are ways to treat PCOS:

  • Medications: Oral contraceptives and antiandrogens help alleviate PCOS symptoms and reduce androgen levels. However, increased androgen levels lead to health complications such as insulin resistance, diabetes, increased cholesterol levels, and heart disease. Metformin may help treat those side effects.
  • Lifestyle: Making lifestyle changes is the first-line treatment for PCOS. Losing 5% to 7% of body weight can produce a regular menstrual cycle, improving pregnancy chances. Anxiety and depression are prevalent in people with PCOS. An improved lifestyle and sense of well-being have improved the quality of life for those with PCOS.

When to See a Healthcare Provider

Call your healthcare provider for the following symptoms:

  • Heavy, irregular, or absent periods
  • Chronic pelvic pain
  • Masculine traits
  • Infertility


Summary

Endometriosis and PCOS are different gynecologic disorders but are both chronic conditions that are difficult to manage. Endometriosis occurs when endometrial tissue travels outside the uterus and damages other organs. PCOS, however, occurs when androgen levels are abnormally elevated, and multiple cysts are found in the ovaries. PCOS results in masculine features and infertility. Endometriosis and PCOS are managed with medications, surgery, and lifestyle changes. Although treatable, neither condition is curable.

A Word From Verywell

Endometriosis and PCOS can be frustrating conditions to manage. Fortunately, they rarely occur together, but each disorder can negatively affect your quality of life. Although living a healthy lifestyle can alleviate the symptoms of endometriosis and PCOS, having a sense of well-being also improves these conditions. It's essential to have social support in addition to medical help when living with endometriosis or PCOS.

Frequently Asked Questions

  • Can endometriosis cause you to gain weight?

    No. Endometriosis does not usually cause weight gain; most people with this condition are average or underweight.

  • Can PCOS trigger endometriosis?

    PCOS and endometriosis are not linked and do not trigger one another.

  • Is PCOS an autoimmune disease?

    PCOS is not considered an autoimmune disease; it is the most common endocrine disorder in women.

  • What is the best diet for PCOS and endometriosis?

    A diet of natural ingredients and rich in fresh fruits and vegetables improves symptoms of endometriosis and PCOS. Exercising also improves quality of life.

  • Can PCOS cause cancer?

    PCOS has been shown to increase the risk of developing certain types of cancer, such as endometrial cancer.

  • Can PCOS and endometriosis cause infertility?

    PCOS and endometriosis have high rates of infertility. About 30% to 50% of people with endometriosis are infertile, and 70% to 80% of people with PCOS experience infertility.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Serenity Mirabito RN, OCN
Serenity Mirabito, MSN, RN, OCN, advocates for well-being, even in the midst of illness. She believes in arming her readers with the most current and trustworthy information leading to fully informed decision making.