PCOS vs Endometriosis: Symptom Overlap, Diagnosis & Coexistence Explained

The main difference between PCOS vs. endometriosis is that they are different types of condition. PCOS (polycystic ovary syndrome) is a hormonal and metabolic disorder that occurs due to insulin resistance and a high level of these hormones called androgens which interferes with the ovulation process. Endometriosis is an inflammatory disorder in which tissue like that of the uterus develops outside the uterus and leads to pain and scarring. Both may lead to pelvic pain, irregular periods and fertility issues, making them easy to mix up with each other and it is possible to get both. Well, here is how they differ, overlap and are diagnosed.

TL;DR: Key takeaways

• PCOS is a hormonal and metabolic condition involving insulin resistance and high androgens.

• Endometriosis is an inflammatory condition where tissue grows outside the uterus.

• Both can cause irregular or painful periods, pelvic discomfort, and infertility.

• PCOS is more linked to missed or absent periods; endometriosis to severe period pain.

• You can have both conditions at the same time, and each needs specialist diagnosis.

What is PCOS?

Polycystic ovary syndrome (PCOS) is a common hormonal disorder in women and men of reproductive age. It is a hormone imbalance and metabolism issue at its core and not a disease of tissue growth.

Many women with PCOS have insulin resistance (insulin resistance means that the cells are less responsive to insulin) and the ovaries may produce more androgens or “male” hormones. These factors interfere with normal ovulation, resulting in irregular or absent periods and may cause small follicles to build up on the surface of the ovary. The Cleveland Clinic says that the symptoms of PCOS include irregular periods, features of excess androgen, and metabolic effects. The most important point to keep in mind is that PCOS is a hormonal and metabolic disorder.

What is endometriosis?

Endometriosis is quite a different disease. This inflammatory disorder in which tissue that normally lines the uterus develops elsewhere, such as on the fallopian tubes, on the ovaries and on other pelvic organs.

This displaced tissue is influenced by hormonal changes and menstruates every month, but the tissue has nowhere to go, which causes inflammation, scarring and adhesion, resulting in pain and possibly infertility. Endometriosis, according to the American College of Obstetricians and Gynecologists, is one of the most common causes of chronic pelvic pain. It is staged from 1-4 according to extent. The difference between PCOS and endometriosis is that in PCOS, the tissue is present in the usual place while in endometriosis, it grows in places where it shouldn't, causing inflammation.

PCOS vs endometriosis: the key differences

Although both affect the reproductive system and fertility, they are fundamentally different conditions. Understanding the difference between PCOS and endometriosis clarifies why they are diagnosed and managed differently.

Here is how they compare:

• Type of condition: PCOS is hormonal and metabolic; endometriosis is inflammatory tissue disease.

• Root cause: PCOS involves insulin resistance and high androgens; endometriosis involves tissue growing outside the uterus.

• Periods: PCOS typically causes irregular, infrequent, or missed periods; endometriosis is more associated with very painful periods that may be regular.

• Pain: Severe pelvic and period pain is a hallmark of endometriosis; PCOS is less defined by pain.

• Other signs: PCOS often involves acne, excess hair growth, and weight changes; endometriosis often involves pain with sex, bowel movements, or urination.

The simplest way to hold the distinction: PCOS is primarily about hormones and metabolism, while endometriosis is primarily about inflammation and tissue, the Mayo Clinic and endometriosis guidance indicate. That difference shapes everything about each condition.

Symptoms: where they overlap and differ

The reason these conditions get confused is a real overlap in some symptoms, even though their distinctive features differ. Sorting out pcos or endometriosis starts with recognizing both.

Overlapping symptoms can include:

• Pelvic pain or discomfort

• Menstrual irregularities

• Difficulty getting pregnant (infertility)

More characteristic of PCOS: irregular, infrequent, or absent periods; acne; excess facial or body hair (hirsutism); scalp hair thinning; and weight gain or difficulty losing weight, reflecting its hormonal and metabolic nature.

More characteristic of endometriosis: severe menstrual cramps, chronic pelvic pain, deep pain during sex, and pain with bowel movements or urination, reflecting its inflammatory nature.

The biggest clue is often the period pattern and pain: PCOS leans toward missed or irregular periods with metabolic and androgen signs, while endometriosis leans toward severe period pain, the Office on Women's Health notes. Still, because both affect fertility and cycles, evaluation is needed to be sure.

Can you have both PCOS and endometriosis?

One of the frequent questions is, can you also suffer from PCOS and endo? Yes, it is possible to have both at the same time.

They're different conditions but not mutually exclusive and some people have both. This can add to the mix of confusion, though, as you may have the irregular periods and metabolic symptoms of PCOS and the intense pain of endometriosis. If you have pcos and endometriosis at the same time, it can also make it more challenging to conceive and you will need to deal with both of these conditions in treatment. One of the reasons for the evaluation being important is because of this overlap; if a person doesn't have all the symptoms of one diagnosis, or if a person treats one diagnosis and symptoms don't go away. If this matches your experience, it is important to talk with your clinician about both.

How each condition is diagnosed

Because PCOS and endometriosis are such different conditions, they are diagnosed in different ways, though both begin with your symptoms and history. Knowing the process helps you understand what to expect.

PCOS is typically diagnosed using a combination of criteria: a clinician looks for irregular ovulation or periods, signs or blood tests indicating excess androgens, and sometimes ultrasound showing the ovaries' appearance, after ruling out other causes. No single test confirms it; it is a clinical diagnosis based on the overall pattern. Endometriosis, by contrast, can be suggested by symptoms and imaging, but the definitive diagnosis usually requires laparoscopy, a minimally invasive surgery to see the implants directly, the ACOG notes. Both conditions are commonly underdiagnosed and can take years to identify, so seeking a knowledgeable clinician matters if your symptoms are dismissed.

Getting answers and treatment

If these symptoms sound familiar, the most valuable step is getting a proper evaluation, since both conditions are treatable and pinning down which one (or both) you have is the key to effective care. You do not have to keep guessing.

Treatments differ by condition: PCOS care focuses on managing hormones, insulin sensitivity, symptoms, and fertility goals, while endometriosis care centers on managing pain, suppressing the disease, and often surgery. Because the right path depends on an accurate diagnosis, connecting with a gynecologist or, for PCOS, sometimes an endocrinologist, is key. A practical first step is talking with a clinician about your symptoms and getting pointed toward the right evaluation. Telehealth makes that initial conversation accessible: a licensed clinician can discuss your symptoms, help with initial guidance, and direct you toward appropriate specialist care, without a long wait. To be clear, diagnosing and treating these conditions ultimately requires in-person specialist care and testing that telehealth itself does not provide, but it helps you take that first step. If you are unsure what your symptoms might mean, you can describe them to August, a free AI health assistant, to help you understand your options and prepare for a conversation with a clinician. It is a starting point, not a diagnosis.