Endometriosis vs. PCOS: How to Tell the Difference

When it comes to women’s reproductive health, two conditions often come up in conversation: Endometriosis and Polycystic Ovary Syndrome (PCOS). Both are common, both can affect fertility, and both can significantly impact a woman’s quality of life. Yet, despite their prevalence, they are frequently misunderstood—and sometimes even confused with one another.

Because endometriosis and PCOS share overlapping symptoms such as irregular periods, pelvic pain, and infertility, many women struggle to understand what exactly is happening with their bodies. Even healthcare providers may initially misdiagnose one as the other.

So, what’s the difference between the two? And how can you tell whether you have endometriosis, PCOS, or possibly both? Let’s break it down.

What is Endometriosis?

Endometriosis is a condition in which tissue similar to the lining of the uterus (the endometrium) grows outside of the uterus. These endometrial-like cells can implant on the ovaries, fallopian tubes, pelvic lining, or other organs.

Each month, these tissues respond to hormonal changes—thickening, breaking down, and bleeding—just like the uterine lining. However, unlike menstrual blood that exits the body, this tissue has no way to leave. This leads to inflammation, scarring, adhesions, and often debilitating pain.

Common Symptoms of Endometriosis:

• Painful periods (dysmenorrhea)
• Chronic pelvic pain
• Pain during or after sex
• Painful bowel movements or urination during periods
• Heavy or irregular bleeding
• Infertility
• Fatigue

Endometriosis affects an estimated 1 in 10 women of reproductive age, but diagnosis is often delayed, sometimes by years, due to the normalization of period pain and lack of awareness.

What is PCOS?

Polycystic Ovary Syndrome (PCOS) is a hormonal and metabolic disorder characterized by an imbalance of reproductive hormones. Women with PCOS often produce higher levels of androgens (male hormones), which disrupt the normal development and release of eggs.

Instead of regular ovulation, the ovaries may develop multiple small follicles (often called “cysts,” though they’re actually immature follicles) that don’t release eggs as they should.

Common Symptoms of PCOS:

• Irregular or absent periods
• Excess hair growth (hirsutism) on the face, chest, or back
• Acne or oily skin
• Thinning hair or male-pattern baldness
• Weight gain or difficulty losing weight
• Darkened patches of skin (acanthosis nigricans)
• Infertility

PCOS affects about 1 in 10 women of reproductive age worldwide, making it one of the most common causes of infertility.

How Endometriosis and PCOS Differ

While both conditions can impact reproductive health, they are fundamentally different.

• Underlying cause: Endometriosis is caused by tissue growth outside the uterus, while PCOS stems from a hormonal imbalance.
• Pain: Endometriosis is strongly linked with chronic pelvic pain and painful periods. PCOS usually does not cause severe pain unless a cyst ruptures.
• Periods: Endometriosis often causes heavy, painful, or irregular bleeding. PCOS is associated with irregular, infrequent, or completely absent periods.
• Fertility impact: With endometriosis, scarring and adhesions can block the fallopian tubes, preventing conception. With PCOS, ovulation itself is disrupted, making it hard to release eggs regularly.
• Other body effects: Endometriosis mainly affects the pelvic area, whereas PCOS can cause whole-body symptoms such as weight gain, excess hair growth, and metabolic problems like insulin resistance.

Can You Have Both?

Yes. Some women have both endometriosis and PCOS, which can complicate diagnosis and treatment. For instance, a woman might have the irregular cycles typical of PCOS along with the severe pain associated with endometriosis. Having both conditions increases the challenges around fertility and requires specialized care.

Why the Confusion?

The confusion between endometriosis and PCOS often comes from overlapping symptoms:

• Both can cause irregular menstrual cycles.
• Both can make it harder to conceive.
• Both can cause ovarian cysts (though they form differently).

However, the type of pain and the hormonal symptoms usually set them apart. Endometriosis is mainly a pain-driven condition, while PCOS is more about hormonal imbalance and metabolic issues.

How Are They Diagnosed?

Endometriosis Diagnosis:

• Medical history and pelvic exam
• Ultrasound or MRI (helpful but not always definitive)
• Laparoscopy (minimally invasive surgery to confirm diagnosis)

PCOS Diagnosis:

Doctors generally follow the Rotterdam Criteria, which require at least two of the following:

1. Irregular or absent ovulation
2. Excess androgens (clinical signs like hirsutism, or lab evidence)
3. Polycystic ovaries on ultrasound

Blood tests for hormone levels and glucose tolerance are also common.

Treatment Options

Endometriosis Treatments:

• Medications: Pain relievers, hormonal therapies (pills, IUDs, injections).
• Surgery: Laparoscopic removal of lesions and adhesions.
• Fertility support: IVF or assisted reproductive technologies if natural conception is difficult.

PCOS Treatments:

• Lifestyle changes: Diet, exercise, and weight management improve symptoms and fertility.
• Medications: Birth control pills to regulate cycles, metformin for insulin resistance, fertility medications like clomiphene.
• Cosmetic management: Treatments for excess hair and acne.

Living with Endometriosis or PCOS

Both conditions are chronic but manageable. With the right care, women can reduce symptoms, improve fertility, and enhance their quality of life.

• Awareness: Recognizing symptoms early is crucial.
• Medical support: Consulting a gynecologist who specializes in women’s reproductive health ensures proper diagnosis and tailored treatment.
• Emotional support: Living with chronic conditions can be isolating—support groups and counseling can make a difference.

Final Thoughts

While Endometriosis and PCOS are distinct conditions, they both highlight an important truth: women’s pain and symptoms should never be dismissed. If you have painful periods, irregular cycles, or difficulty conceiving, it’s essential to seek medical advice.

Early diagnosis and the right treatment plan can make all the difference—not just for fertility, but for overall health and well-being.

Take the Next Step: Consult Dr. Sunita Arora

If you’re struggling with painful periods, irregular cycles, or fertility issues, it’s time to get clarity. Don’t let confusion between endometriosis and PCOS delay the care you deserve.

Dr. Sunita Arora, Obstetrics & Gynecologist, specializes in diagnosing and managing complex women’s health conditions with compassion and expertise. Whether it’s endometriosis, PCOS, or both, she provides personalized treatment plans to help women reclaim their health, confidence, and quality of life.

Take charge of your reproductive health today—book a consultation with Dr. Sunita Arora and get the answers you’ve been searching for.