Endometriosis. Adenomyosis. PMOS.
Three conditions that are often mentioned in the same conversations. They can share symptoms, they can exist at the same time and yet they are three different conditions.
So… what is actually what? Here’s the simple breakdown.
ENDOMETRIOSIS (ENDO):
Endometriosis is a chronic inflammatory disease where tissue similar to the lining of the uterus is found outside the uterus. While it most commonly affects structures within the pelvis, Endometriosis is not confined to the reproductive organs or even the pelvis. It has been documented on or involving the bowel, bladder and urinary tract, diaphragm, lungs/thoracic cavity, abdominal wall and, in rare cases, other distant organs and structures throughout the body.
Despite a very common misconception, Endometriosis is not simply the lining of the uterus growing in the wrong place. The tissue is similar to the endometrium, but it is not identical.
What can Endometriosis feel like?
Symptoms can include:
• Severe period pain
• Chronic pelvic pain
• Pain during or after sex
• Pain with bowel movements
• Pain when urinating
• Abdominal bloating
• Fatigue
• Heavy bleeding
• Fertility difficulties
But Endometriosis can look completely different from one Warrior to another.
The severity of someone's pain also doesn't necessarily tell us the extent of their disease.
ADENOMYOSIS (ADENO):
Where is it? Within the muscular wall of the uterus.
This is where Endometriosis and Adenomyosis are commonly confused.
Adenomyosis occurs when tissue similar to the lining of the uterus is found within the muscle of the uterus, known as the myometrium.
Unlike Endometriosis, which exists outside the uterus, Adenomyosis specifically affects the uterus.
What can Adenomyosis feel like?
Symptoms can include:
• Extremely painful periods
• Heavy or prolonged menstrual bleeding
• Chronic pelvic pain
• Cramping
• Pelvic pressure or heaviness
• Abdominal bloating
• Pain during sex
Some people with Adenomyosis experience very heavy bleeding and debilitating pain, while others may have few or even no noticeable symptoms.
Adenomyosis and Endometriosis can also occur together.
This is important because someone experiencing pelvic pain may not necessarily have only one condition contributing to their symptoms.
Polyendocrine Metabolic Ovarian Syndrome - (PMOS) (FORMERLY KNOWN AS PCOS):
What is it? A hormonal, metabolic and ovarian syndrome.
In 2026, the condition historically known as Polycystic Ovary Syndrome (PCOS) was renamed: Polyendocrine Metabolic Ovarian Syndrome (PMOS).
And despite the old name, PMOS was never simply about ovarian “cysts”.
The structures historically described as cysts are actually ovarian follicles, and someone does not need to have polycystic-appearing ovaries to have PMOS.
PMOS is a complex syndrome involving interconnected hormonal, metabolic, ovarian and reproductive factors.
What can PMOS look like?
Features and associated symptoms can include:
• Irregular or absent periods
• Irregular or absent ovulation
• Higher androgen levels
• Excess facial or body hair
• Acne
• Scalp hair thinning
• Fertility difficulties
• Insulin resistance and other metabolic concerns
• Changes in weight or difficulty with weight management
• Mental health and body image impacts
Not every person with PMOS will experience all of these.
So what's the difference?
Think about it this way:
ENDOMETRIOSIS
→ Tissue similar to the uterine lining grows outside the uterus that can grow on every major organ in the body.
ADENOMYOSIS
→ Tissue similar to the uterine lining is found within the muscular wall of the uterus.
PMOS
→ A hormonal, metabolic and ovarian syndrome that can affect ovulation, menstrual cycles, androgen levels, metabolic health and more.
Three different conditions.
But here's where things become complicated:
You can have more than one.
Someone can have Endometriosis and Adenomyosis.
Someone can have Endometriosis and PMOS.
Someone can have Adenomyosis and PMOS.
And yes - someone can live with all three.
Why can they be so confusing?
Because symptoms can overlap.
- Irregular periods.
- Painful periods.
- Heavy bleeding.
- Pelvic pain.
- Fertility difficulties.
- Bloating.
- Fatigue.
- Changes to your menstrual cycle.
These symptoms don't automatically point towards one specific diagnosis.
For example, severe pelvic pain shouldn't automatically be blamed on PMOS simply because someone already has a PMOS diagnosis.
Likewise, someone diagnosed with Endometriosis may have another condition contributing to heavy bleeding or chronic pain.
One diagnosis doesn't mean there can't be another.
And that's an incredibly important message for anyone who still feels that something isn't right.
What about a Hysterectomy?
This is another area where understanding the difference matters.
Removing the uterus is not considered a cure for Endometriosis, because Endometriosis exists outside the uterus.
For Adenomyosis, however, the disease is located within the uterus, meaning hysterectomy is considered the definitive treatment when appropriate for the individual.
And a hysterectomy does not automatically treat the underlying endocrine and metabolic features of PMOS.
This is exactly why knowing what condition is causing which symptoms can be so important when discussing treatment options.
Three Conditions. Three Different Stories.
Endometriosis, Adenomyosis and PMOS are often grouped together under the enormous umbrella of reproductive and women's health.
But they deserve to be understood individually.
Endometriosis isn't Adenomyosis.
Adenomyosis isn't PMOS.
PMOS isn't Endometriosis.
And having one doesn't protect you from having another.
If there's one thing we want you to take away from this blog, it's this:
Your symptoms deserve investigation, even if you already have a diagnosis.
If something changes, if your symptoms don't make sense, or if you feel like your current diagnosis doesn't explain everything you're experiencing, you deserve to ask questions.
You deserve to understand your body.
And you deserve to be heard.
A Note From The Endo Essentials:
The Endo Essentials is a lived experience community and awareness platform. We are not doctors, and this information is provided for general education and awareness only. It should not be used to diagnose Endometriosis, Adenomyosis, PMOS or any other medical condition.
If you're experiencing symptoms or have concerns about your menstrual, pelvic, hormonal or reproductive health, please speak with your GP or an appropriately qualified healthcare professional.
For serious or urgent medical concerns, please seek urgent medical assistance or attend your nearest emergency department.