Endometriosis vs. PCOS: Differences and similarities

Many women wonder about the differences between PCOS and endometriosis. At first glance, they may seem similar, as both conditions impact the female reproductive system.  However, each has unique symptoms, causes, and implications. Here, we’ll dive into what sets these conditions apart and why understanding each is essential for reproductive health.

In a nutshell:

• While both PCOS and endometriosis affect the reproductive system, PCOS is a hormonal imbalance condition, whereas endometriosis involves the growth of uterine-like tissue outside the uterus.
• Both conditions can lead to heavy menstrual bleeding and challenges with conception, but endometriosis often causes pain during periods, while PCOS may result in excess hair growth and acne.
• PCOS is often diagnosed with hormone tests and ultrasound, while endometriosis requires a laparoscopy for a definitive diagnosis.
• A family history of either condition can increase your risk, and both are linked to early menstruation.
• Both conditions have treatment plans that can help manage symptoms and improve quality of life. Speaking with a healthcare provider is essential for effective diagnosis and care. 

Understanding endometriosis and PCOS 

Before we get into the similarities and differences between endometriosis and PCOS, it's important to understand a little about what these conditions are.

Endometriosis 

The uterus is lined with endometrial tissue. Endometriosis occurs when this tissue grows outside the uterus, often on the ovaries, fallopian tubes, or pelvic lining. This displaced tissue continues to act as it would inside the uterus, thickening, breaking down, and bleeding during each menstrual cycle. However, with no exit for this tissue, it can cause inflammation, scarring, and significant pain.

PCOS

PCOS, or Polycystic Ovary Syndrome, is a hormonal condition that commonly leads to irregular ovulation. Women with PCOS may develop small cysts on the ovaries, which can contribute to hormonal imbalances, particularly increased levels of androgens (male hormones). These hormonal fluctuations often lead to symptoms such as irregular period, acne, hair growth on the face and body, and sometimes difficulties with conception.

PCOS vs. Endometriosis: Symptoms 

While both conditions can cause heavy menstrual bleeding and difficulties with conception, the broader range of symptoms differs.

Common PCOS symptoms

PCOS symptoms vary widely from one person to another, with some experiencing severe symptoms and others having few or no symptoms. Common signs include: 

• Heavy menstrual bleeding
• Difficulty getting pregnant
• Weight Gain
• Missed or irregular periods
• Cysts on the ovaries
• Excess hair growth
• Acne
• Thinning hair
• Oily skin
• Dark or thick patches on the skin

Common endometriosis symptoms

Endometriosis symptoms also range in intensity, with some women experiencing debilitating pain and others having no symptoms at all. The severity of symptoms doesn’t always match the severity of the condition. Typical endometriosis symptoms include:

• Painful periods
• Heavy menstrual bleeding
• Pain during bowel movements or urination, particularly during menstruation
• Chronic lower back and pelvic pain
• Digestive issues like diarrhea, constipation, and bloating
• Difficulty getting pregnant

Causes of PCOS and endometriosis

Despite a few overlapping symptoms, the causes of PCOS and endometriosis differ significantly.

Cause of PCOS 

The exact cause of PCOS is still not fully understood, but experts believe it’s rooted in endocrine (hormonal) imbalance. Normally, women ovulate once a month, releasing an egg that may be fertilized, which can lead to pregnancy. In PCOS, hormonal imbalances interfere with regular ovulation, leading to cyst formation on the ovaries and high levels of androgens. Insulin resistance is also common in PCOS, potentially leading to weight gain and exacerbating symptoms.

Cause of endometriosis 

The cause of endometriosis still remains unknown. The most common theory is that it's caused by retrograde menstruation, where menstrual blood flows backward through the fallopian tubes into the pelvic cavity. Other theories suggest that stem cells or immune system dysfunction may play a role, allowing endometrial-like cells to grow outside the uterus.

Risk factors for endometriosis and PCOS 

Like most disorders, there are things that increase your risk of developing endometriosis or PCOS. 

Risk factors for endometriosis

Risk factors for endometriosis include: 

• Family history (especially if a mother or sister has the condition)
• Early menstruation (starting your period before age 11)
• A menstrual cycle shorter than 27 days
• Heavy periods that last 7 days or longer
• Structural abnormalities that affect menstrual flow

Risk factors for PCOS

Risk factors for PCOS include: 

• Family history of PCOS
• Type 2 diabetes
• Fast weight gain
• Obesity or significant weight gain
• Hyperandrogenism (higher levels of androgens)
• Premature puberty (before age 9)
• Epilepsy or related neurological conditions

Do I have endometriosis or PCOS?

If you suspect you have PCOS or endometriosis, visiting a healthcare provider is essential. Here’s what to expect from the diagnostic process for each condition.

Diagnostic steps for PCOS

Diagnosis typically starts with a physical exam, including a pelvic exam to evaluate reproductive health. Your doctor may check for other indicators such as weight gain and blood sugar levels. Blood tests can also measure hormone levels, including androgens and insulin. Ultrasound imaging of the ovaries can reveal cysts or an enlarged ovary, which may support a PCOS diagnosis.

Diagnostic steps for Endometriosis

Diagnosing endometriosis usually requires an ultrasound or MRI to visualize abnormalities, but these alone are often inconclusive. The only definitive diagnostic method is laparoscopy, a minimally invasive surgery that allows doctors to view and sometimes remove endometrial tissue growing outside the uterus.

Can you have PCOS and endometriosis?  

Yes, it’s possible to have both conditions. A study published by the National Library of Medicine found that about 1 in 20 women who underwent surgery to check for endometriosis had both endometriosis and PCOS. Among the general population, the estimate is closer to 1 in 50 women.

Can endometriosis be mistaken for PCOS? The answer is yes as well. Both conditions are difficult to diagnose, and some of the symptoms overlap. Consulting a specialist can help clarify your situation and determine the most effective treatment options.

Do PCOS and endometriosis go together? 

There are some similarities between the two conditions. They are both disorders of the female reproductive system, and they are both linked to abnormal periods.  Hormonal abnormalities are also common in both conditions. Another similarity is that having a family history of these disorders or early periods increases your risk. 

However, despite these similarities, they are different conditions with different causes. Having one disorder does increase your risk of having the other, but there's not a clear link between them. 

If you are wondering can PCOS turn into endometriosis, the answer is no. One condition can not turn into the other, and many women have only one of these conditions.

Do PCOS and endometriosis worsen each other?

PCOS and endometriosis both involve hormonal imbalances, irregular periods, and increased risk of reproductive health issues. While having one may raise your risk of developing the other, the two conditions do not directly worsen each other. However, the presence of both can increase the complexity of managing symptoms and achieving a balanced treatment plan.

Final verdict 

While PCOS and endometriosis may share some symptoms and risk factors, they are separate conditions with distinct causes and health implications. If you suspect you have symptoms related to either condition, consulting your healthcare provider can help clarify your diagnosis and lead to a treatment plan that supports your reproductive health.

Frequently asked questions:

Can PCOS turn into endometriosis?

PCOS and endometriosis are distinct conditions and cannot "turn into" each other. They may coexist, but one does not cause the other.

Which condition is more severe: PCOS or endometriosis?

Severity varies between individuals and depends on each condition's symptoms and impact on daily life. For some, endometriosis pain is more severe, while others struggle more with PCOS symptoms like weight gain and insulin resistance. There is no straightforward answer, as the effect of each condition can differ widely.

Does endometriosis cause facial hair?

Facial hair growth is more commonly associated with PCOS due to elevated androgens. However, endometriosis can occasionally cause facial hair due to estrogen imbalances or side effects from medications.

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References: 

https://www.hopkinsmedicine.org/health/conditions-and-diseases/polycystic-ovary-syndrome

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10472311/

https://www.yalemedicine.org/conditions/endometriosis

https://www.mayoclinic.org/diseases-conditions/pcos/symptoms-causes/syc-20353439

https://www.who.int/news-room/fact-sheets/detail/endometriosis

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