You've got pelvic pain, periods that don't behave, and a growing pile of Google tabs that all say something different. One says PCOS. Another says endometriosis. A few say both, which is somehow less helpful, not more.

Here's the promise: by the end of this article, you'll actually understand what separates these two conditions, where they overlap, why doctors sometimes confuse them, and what it means if you've got both. No jargon dump, no fear-mongering, just the mechanics explained properly.

The short version: PCOS is a hormonal and metabolic condition built around irregular ovulation, excess androgens and often insulin resistance. Endometriosis is a structural, inflammatory condition where tissue similar to the uterine lining grows outside the uterus. They can look similar on the surface. Underneath, they're doing genuinely different things to your body. And yes, you can have both at once.

What Actually Is PCOS?

Short answer: PCOS is a hormonal and metabolic condition marked by irregular ovulation, higher androgen levels, and often insulin resistance.

Polycystic Ovary Syndrome is not, despite the name, a disease of "cysts on the ovaries." That naming has caused years of confusion. What's actually going on is a hormonal and metabolic pattern that disrupts ovulation.

Here's the mechanism in plain English. In a typical cycle, your ovaries mature and release an egg roughly once a month. With PCOS, that process gets interrupted, often before it even properly starts. Follicles begin developing but don't consistently reach ovulation. On an ultrasound, this can look like a string of small, immature follicles around the edge of the ovary, which is where the old "polycystic" label came from.

This irregular ovulation is closely tied to two other things: excess androgens (hormones like testosterone that everyone has, but which run higher than average in PCOS) and insulin resistance, where your cells don't respond to insulin as efficiently as they should. These three factors, irregular ovulation, high androgens and insulin resistance, feed into each other in a loop. Higher insulin levels can push androgen production up. Higher androgens can disrupt ovulation further. It's a hormonal feedback loop, not a single broken part.

That's why PCOS symptoms show up in places that don't obviously look "reproductive": acne along the jawline, unwanted hair growth, scalp hair thinning, weight that's stubborn to shift, and cycles that arrive whenever they feel like it, if at all.

Not everyone with PCOS has ovarian cysts

One of the biggest sources of confusion is the name itself. Plenty of people diagnosed with PCOS have perfectly normal-looking ovaries on ultrasound, because the diagnosis depends on meeting at least two of three criteria, not on cysts being visible. Equally, plenty of people without PCOS have follicles on their ovaries that look similar on a scan. The ultrasound is one piece of evidence, not the whole story, which is part of why PCOS gets missed or misapplied so often in casual conversation.

There's also a spectrum here. Some people with PCOS have textbook symptoms across the board. Others have mostly metabolic signs with fairly regular cycles, or mostly cycle irregularity with no visible skin or hair symptoms at all. PCOS is not one uniform experience, which is exactly why cookie-cutter advice like "just lose weight" so often misses the mark.

The research on this is actually pretty clear: PCOS is best understood as a whole-body hormonal and metabolic condition, not just an ovarian one. If PCOS is part of your picture, a daily myo-inositol supplement like Myoplus may help support hormonal balance alongside the basics of sleep, movement and nutrition your doctor will likely recommend.

What Actually Is Endometriosis?

Short answer: Endometriosis is tissue similar to the uterine lining growing outside the uterus, causing inflammation, scarring and often severe pain.

Endometriosis works on a completely different mechanism. Each month, the lining of your uterus (the endometrium) builds up and then sheds as your period. Endometriosis happens when tissue that behaves like this lining grows in places it shouldn't, most commonly on the ovaries, fallopian tubes, the lining of the pelvis, or the bowel and bladder.

That misplaced tissue still responds to your hormonal cycle. It thickens, breaks down and tries to "bleed" in roughly the same rhythm as your period, except it has nowhere to go. There's no exit route, so it triggers local inflammation, and over time, can lead to scar tissue and adhesions, where organs or tissue stick together that normally wouldn't.

This is the piece that explains why endometriosis pain often feels so different from ordinary period pain. It's not just a heavier version of period cramps. It's chronic inflammation acting on tissue and nerves in places your body never expected it. That's also why pain can show up outside your period entirely, and why bowel or bladder symptoms often come along for the ride when endometriosis sits near those organs.

We don't fully understand why endometriosis develops in some people and not others. Genetics, immune function and retrograde menstruation (where some menstrual tissue flows backwards through the fallopian tubes rather than out of the body) are all part of the current picture, but none of them fully explain it on their own. Your body is trying to tell you something even when the exact "why" is still being researched.

Why the location of the tissue matters

Where the tissue ends up has a big effect on which symptoms show up. Endometriosis on or near the ovaries can affect egg quality and fertility. Endometriosis on the bowel or bladder can cause pain or changes in bowel habits, particularly around your period, which is why these symptoms are sometimes mistaken for IBS rather than investigated as a reproductive issue. This is also why two people with endometriosis can have completely different symptom profiles despite sharing the same underlying condition.

How Do PCOS and Endometriosis Symptoms Overlap and Differ?

Short answer: Both can cause irregular or heavy periods, pelvic pain and fertility difficulty, but the pain pattern and extra symptoms usually differ.

This is where the confusion kicks in, because on paper, the symptom lists look similar. Both conditions can involve irregular or heavy periods. Both can involve pelvic pain. Both can make it harder to conceive. If you've only skimmed a symptom checklist, it's genuinely easy to land on the wrong one, or assume you can only have one.

Look closer, though, and the pattern of symptoms tends to diverge.

Period pain: cyclical versus constant

PCOS-related pelvic discomfort, when it happens, tends to be milder and closely tied to your cycle. Endometriosis pain is often more severe, can appear well before or after your period (or persist throughout the month), and frequently comes with pain during sex, bowel movements or urination, particularly around your period. That's a meaningful red flag, not just "bad period pain."

What's driving the irregularity

With PCOS, irregular periods usually mean infrequent or unpredictable ovulation, so cycles can be long, short or absent altogether. With endometriosis, cycles can still be fairly regular, but heavier and significantly more painful.

Here's a side-by-side to keep it straight:

Feature	PCOS	Endometriosis
Core mechanism	Hormonal and metabolic; irregular ovulation, excess androgens, often insulin resistance	Structural and inflammatory; uterine-like tissue growing outside the uterus
Typical pain pattern	Usually milder, cycle-linked when present	Often severe, can occur outside your period too
Cycle pattern	Irregular, infrequent or absent periods	Often regular but heavier and more painful
Other common symptoms	Acne, excess hair growth, scalp thinning, weight changes	Bowel and bladder symptoms, fatigue, pain during sex
Fertility impact	Often linked to irregular or absent ovulation	Often linked to inflammation, scarring or blocked tubes
Definitive diagnosis	Rotterdam criteria: symptoms, bloods, ultrasound	Historically laparoscopy; imaging increasingly used

Two things worth repeating here: this table shows typical patterns, not rules. Your PCOS pain might be worse than average. Your endometriosis might be quieter than the textbook. Your body is trying to tell you something specific to you, and a table is a starting point for that conversation, not a verdict.

How Is Each Condition Actually Diagnosed?

Short answer: PCOS is diagnosed using symptoms, blood tests and ultrasound, while endometriosis has historically needed laparoscopy surgery to confirm it.

Here's where the two conditions genuinely part ways, and where a lot of dismissal happens.

Diagnosing PCOS

In the UK, PCOS is typically diagnosed using the Rotterdam criteria, which requires at least two of three features to be present: irregular or absent ovulation, clinical or blood-test signs of excess androgens, and polycystic-looking ovaries on ultrasound.^[1] That means a scan alone isn't enough, and neither is one symptom alone. It's a picture built from multiple pieces of evidence, and other conditions (like thyroid issues) usually need to be ruled out first.

Diagnosing endometriosis

Endometriosis has traditionally been trickier. For decades, laparoscopy, a keyhole surgical procedure where a camera is used to look directly inside the pelvis, has been considered the only way to confirm it definitively.^[2] That's slowly changing. Detailed pelvic ultrasound and MRI, done by specialists experienced in spotting endometriosis, are increasingly used to support a diagnosis and guide treatment planning without surgery being the first step. Guidelines now recognise that a clinical diagnosis, based on symptoms and imaging, can be appropriate before or instead of surgery in many cases.^[2]

The delay problem

This is what I wish someone had told me earlier in my own work in this space: diagnostic delay is not rare, it's closer to the norm. In the UK, the average time from first symptoms to an endometriosis diagnosis is around 8 years.^[3] PCOS diagnosis can also take years of appointments, especially for women whose symptoms don't fit the "classic" presentation, or who are told their irregular periods are "just stress."

Your diagnosis is a starting point, not a verdict, and if you've been waiting a long time for one, that delay is a systemic problem, not a sign you were exaggerating.

Can You Have PCOS and Endometriosis at the Same Time?

Short answer: Yes. Having both conditions together is more common than many people realise, and it can make symptoms and treatment planning more complex.

Short answer, expanded: yes, and this trips up a lot of people, including some clinicians, because the two conditions are usually treated as separate boxes. In practice, PCOS and endometriosis can and do coexist.

Research on how often this happens is still developing, and estimates vary between studies, but the direction is consistent: having one of these conditions doesn't rule out the other, and researchers have observed the two occurring together more often than would be expected by chance.^[4] A shared hormonal and inflammatory backdrop may partly explain why.

Practically, this matters because if you've been told you have PCOS but something still feels "off," particularly around pain that doesn't fit the usual PCOS pattern, it's worth raising endometriosis as a possibility with your doctor, and vice versa. Root cause, not symptom suppression, means not stopping at the first diagnosis if your symptoms don't fully add up.

Having both also complicates treatment, because some approaches that help one condition (like certain hormonal contraceptives) can be genuinely useful for both, while others need to be balanced carefully against each other, particularly around fertility planning. This is a conversation for a gynaecologist who takes both conditions seriously, not a reason to panic.

If you already have a PCOS diagnosis and something still doesn't add up, pain that's worse than your PCOS should reasonably cause, pain outside your period, or bowel and bladder symptoms alongside your usual PCOS pattern, it's worth naming endometriosis specifically when you ask for a referral. Vague requests like "I still don't feel right" get vague responses. Specific symptom patterns get taken more seriously.

How Do Treatment Approaches Differ?

Short answer: PCOS treatment focuses on metabolic and hormonal balance; endometriosis treatment focuses on pain control and reducing tissue activity.

Because the underlying mechanisms are different, treatment tends to point in different directions too, even though there's some overlap in the tools used.

PCOS treatment approaches

PCOS management generally centres on the hormonal and metabolic loop described earlier: supporting insulin sensitivity, regulating cycles and managing androgen-related symptoms. That can include lifestyle adjustments around movement, sleep and nutrition, medications such as metformin for insulin resistance or hormonal contraception to regulate cycles, and fertility-specific treatment if you're trying to conceive. It's not a magic fix. But giving your body consistent support, rather than a quick crash diet, tends to make the biggest long-term difference.

Endometriosis treatment approaches

Endometriosis treatment is generally aimed at reducing pain and limiting the activity of the misplaced tissue. Options a specialist might discuss include pain management strategies, hormonal treatments that reduce oestrogen's effect on the tissue, and surgery to remove or reduce endometrial lesions in more significant cases.^[2] The right approach depends heavily on your symptoms, how much the condition is affecting your life, and whether you're trying to conceive now or in future, which is exactly why this needs a specialist conversation rather than a generic checklist.

Where they meet

Both conditions benefit from a clinician who treats you as a whole person rather than a single symptom. Hormonal literacy isn't complicated, it's just rarely taught, and understanding which system is driving your symptoms (metabolic and ovulatory, or inflammatory and structural) helps you ask sharper questions and push back when a treatment plan doesn't match what's actually going on in your body.

Lifestyle factors like sleep, movement, stress and nutrition tend to show up on both sides of the treatment conversation too, not because they resolve either condition on their own, but because chronic inflammation and hormonal regulation are both influenced by the basics. It's not a magic fix. But it gives your body what it's often missing, which is consistent, unglamorous support rather than another restrictive plan you'll abandon by February.

Why Does It Take So Long to Get a Diagnosis?

Short answer: Both conditions are chronically under-recognised, and period pain is still routinely normalised rather than investigated.

Let's talk about the part that doesn't show up in a symptom list: being told your pain is normal when it clearly isn't. This is the shared thread running through almost every conversation MyOva has with people managing PCOS or endometriosis. You mention the pain, the exhaustion, the periods that derail your week, and you get "that sounds like a normal period" or "try painkillers and see how you get on."

You're not imagining it. Both conditions are genuinely, well-documented as under-diagnosed and dismissed, not because the symptoms are subtle, but because period pain and irregular cycles have been culturally treated as background noise for too long. Endometriosis in particular sits with one of the longest average diagnostic delays of any common condition in the UK.^[3]

If you've been dismissed, that's not a reflection of how "bad" your case is. Severity of symptoms doesn't reliably predict how visible either condition is on a scan, and it definitely doesn't predict how seriously you'll be taken in a ten-minute appointment. If something feels wrong, you're allowed to ask for a second opinion, request a referral to a specialist, or keep a symptom diary to bring evidence to your next appointment. That's not being difficult. That's advocating for yourself in a system that, frankly, needs you to.

A symptom diary is worth more than it sounds. Note when pain happens relative to your cycle, how it compares to painkillers, and anything that reliably makes it better or worse. That kind of pattern is exactly what helps a doctor distinguish between "this is likely PCOS," "this is likely endometriosis," or "this is worth investigating for both," rather than defaulting to whichever explanation is quickest to hand you.

Frequently Asked Questions

Can you have PCOS and endometriosis at the same time?
Yes. The two conditions can occur together, and doing so can make both symptoms and treatment planning more complex, which is why an accurate, specific diagnosis matters.

Which is worse, PCOS or endometriosis?
Neither is universally "worse." They affect the body differently, PCOS through hormones and metabolism, endometriosis through inflammation and tissue growth, and severity varies hugely between individuals within each condition.

Do PCOS and endometriosis cause infertility the same way?
No. PCOS-related fertility difficulty is usually linked to irregular or absent ovulation. Endometriosis-related fertility difficulty is usually linked to inflammation, scarring or blocked fallopian tubes. Both are manageable with the right specialist support.

How do doctors tell the difference between PCOS and endometriosis?
Doctors look at the pattern of symptoms (especially pain timing), use bloods and ultrasound for PCOS via the Rotterdam criteria, and use imaging or laparoscopy to investigate suspected endometriosis.

Can endometriosis be mistaken for PCOS?
Yes, particularly early on, because both can involve pelvic pain and cycle irregularity. Pain that's more severe, occurs outside your period, or comes with bowel or bladder symptoms should prompt your doctor to look specifically at endometriosis.

Can PCOS turn into endometriosis, or vice versa?
No, one condition doesn't "turn into" the other. They're separate conditions with separate mechanisms, though as covered above, they can exist independently in the same person.

Is pelvic pain always a sign of one of these conditions?
Not always. Pelvic pain has many possible causes. But pain that's severe, worsening, cyclical or affecting your daily life is always worth investigating properly rather than dismissing.

Should I ask for a specific test if I suspect endometriosis?
It's reasonable to ask your GP about a referral to a gynaecologist experienced in endometriosis and to ask what imaging or next steps are appropriate for your symptoms. You know your body better than a ten-minute appointment can capture.

Conclusion

PCOS and endometriosis are two different conditions doing two different things inside your body, one hormonal and metabolic, one structural and inflammatory, and understanding which one (or both) you're dealing with changes how you advocate for yourself, what questions you ask, and what support actually helps.

If there's one thing worth taking from this, it's that your diagnosis is a starting point, not a verdict, whichever condition you land on, or if you're still waiting for an answer at all. Hormonal literacy isn't complicated, it's just rarely taught, and now you know a little more of it than you did ten minutes ago.

Whatever stage you're at, whether newly diagnosed, still waiting for answers, or managing both conditions at once, you deserve a care team that listens properly and a plan built around what's actually happening in your body, not a generic checklist.

Further Reading

Period Pain: When It's Normal and When It's a Red Flag
What's PCOS? The Basics Explained
Best Supplements for Endometriosis: 8 Ingredients Backed by Research

References

1. NICE Clinical Knowledge Summaries. Polycystic ovary syndrome. National Institute for Health and Care Excellence.
2. NICE Guideline NG73. Endometriosis: diagnosis and management. National Institute for Health and Care Excellence.
3. Endometriosis UK. Endometriosis facts and figures.
4. NHS. Endometriosis and Polycystic ovary syndrome (PCOS) overview pages.

This article is for general information only and does not replace advice from your GP or a qualified healthcare professional. Food supplements should not be used as a substitute for a varied and balanced diet. If you're pregnant, breastfeeding, taking medication or managing a diagnosed health condition, check with a healthcare professional before starting a new supplement.

References