Around the world, polycystic ovarian syndrome (PCOS) affects approximately 116 million women and is considered the most common endocrine disorder in women of reproductive age. Does emerging evidence suggest that PCOS autoimmune disease is one consequence of the condition, but is PCOS itself an autoimmune disorder?¹
Let’s explore what PCOS and autoimmune diseases are, their similarities, and the links between PCOS and known autoimmune disorders. We’ll also discuss several treatment options for autoimmune diseases and the importance of seeking medical care to manage your PCOS symptoms and reduce your risk of complications.
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PCOS is a health disorder of the endocrine system that impacts women’s hormone levels. If you have any two of the following three markers, you may be diagnosed with PCOS:²
Higher levels of male hormones called androgens, which include testosterone, DHEA, DHEA-S, and DHT
Enlarged ovaries that may have developed fluid-filled sacs known as follicles around your eggs (polycystic ovaries)
Around 5%–18% of women worldwide are affected by PCOS. In the US, Greece, and Spain, it’s estimated that about 4%–8% of women have the condition. In Pakistan, the prevalence is between 5%–10%.³
The signs and symptoms of PCOS may include:
Infrequent periods (oligomenorrhea)
The absence of periods (amenorrhea)
Obesity or being overweight
Excess hair growth on the face, neck, and other body parts (hirsutism)
Overproduction of hormones by reproductive glands called gonads (hypergonadism)
There are two types of immunity. Innate immunity is present when you’re born. Acquired immunity is learned when your body comes across foreign bodies. It mounts an immune response to attack them so that these invaders can't harm you.
From then on, your immune system will recognize the same foreign bodies if they invade again. It has a memory of the best battle plan to help stop a particular invader.
In autoimmune disease, acquired immunity is faulty because it reacts as if your body’s tissues are foreign bodies. It then mounts an immune response against them, which can lead to multiple health issues. Common symptoms across different types of autoimmune disease include:
Inflammation that causes heat and swelling
Skin rashes or discolorations
Thyroid issues leading to fatigue, muscle aches, and weight gain
Joint aches, pains, and dysfunction or complete loss of function
In many autoimmune diseases, more than one body part may be affected.
The causes of autoimmune diseases are not known. Many are believed to develop due to multiple overlapping factors. The following are potential underlying factors for autoimmune diseases’ development and progress over time.
Numerous genes have been shown to increase the risk of developing autoimmune disease slightly, depending on the condition. Expression of the human leukocyte antigen (HLA) position on a chromosome has shown the strongest association with the development of most autoimmune diseases for which genetic research has been conducted.
Faulty immune system regulation is found across multiple autoimmune diseases studied in animal models, such as problems with T cell functions.
While these faulty immune responses require more human study, what is known is that blood molecules called “autoantibodies” are the key marker for identifying autoimmune diseases. They may also be used to help identify an increased risk for autoimmune diseases before they develop.
Dietary considerations, infections, pollutants, drugs, and stress are all environmental factors that may be linked to autoimmune disease. These are considered the weakest link due to the difficulty in isolating them from other factors to study them in a controlled setting.
Your endocrine system includes the glands that produce hormones. There’s some evidence that transitions in women and girls that involve this system, including puberty, pregnancy, and menopause, may make females more susceptible to developing autoimmune diseases.
There’s increasing evidence that faulty inflammatory responses are linked to autoimmune diseases. T-cell inflammation responses, in particular, are associated with the development of these disorders.⁴
There are over 80 known autoimmune disorders, and some of the most familiar include:
About 24 million people have autoimmune diseases in the US. Most autoimmune diseases don’t have a cure, and treatments to manage the symptoms may continue for life.
PCOS has been linked to several potential causes. Several of these are also possible causes of autoimmune diseases.⁵
There’s limited evidence that certain genes may be linked to the development of PCOS. One study revealed that 32% of sisters and 24% of mothers of PCOS patients also had PCOS, compared to a 4% prevalence in the general population. (Note: In the US, it’s estimated the PCOS prevalence among the general population is 4% to 8%).⁶ ⁷
Some research has revealed that gene coding errors in certain genes involved in regulating androgen hormones may increase these hormones in those with PCOS.
For instance, one study revealed that certain HLA gene expressions were more likely present in women with PCOS than those without the condition. HLA gene variations are also the ones that are most associated with the development of autoimmune diseases.⁸
Some evidence links exposure to excess androgens (male hormones) during the development of the fetus in the womb to the development of PCOS later in life. Women with PCOS have higher levels of androgens and low progesterone levels than those without the condition.⁹
Hormones are also involved in the development of autoimmune diseases. Though the mechanisms are complex and often different for each specific condition, faulty hormonal responses play a part in all autoimmune diseases. One example is the androgen hormones’ role in reducing immunity.
Some research has shown a connection between pro-inflammatory responses and an increase in androgen levels. Higher levels of these androgen hormones, such as testosterone, are one of the markers of PCOS.¹⁰
Likewise, some evidence has linked autoimmune disease development to abnormal inflammatory responses.
When your body’s tissues are resistant to the effects of the hormone insulin, which is produced by the pancreas, this is known as insulin resistance.
If you have insulin resistance, your body produces more insulin to ensure the desired effects of the hormone. This excess insulin may cause the ovaries to produce extra androgen testosterone.
Approximately 65%–70% of women with PCOS have insulin resistance. The incidence is even greater among obese women: 70%–80% of PCOS patients with a BMI greater than 30 are insulin resistant.¹¹
While insulin resistance isn’t considered a general underlying cause of autoimmune diseases, most people who have Type B insulin resistance have an autoimmune disorder.
Dietary factors may have a link to PCOS, specifically obesity. In the US, research has revealed that up to 80% of women with PCOS are obese.¹²
Obesity increases the risk of developing insulin resistance, which may lead to excess production of androgens (hyperandrogenism). Excess androgens are one marker of PCOS.
Similarly, environmental factors such as diet are also one potential cause of autoimmune diseases.
Just like with autoimmune diseases, none of these potential causes of PCOS stand alone but instead are believed to interact to trigger the development of the disease.
In addition to the 24 million people in the US with autoimmune disease, an additional 8 million people nationwide have autoantibodies without being diagnosed with an autoimmune disease.
These molecules in the blood are considered a marker of autoimmune disease or your potential to develop it. They help diagnose whether you have an autoimmune disease and, if so, which one.
Like with autoimmune diseases, people with PCOS have been documented to have certain autoantibodies in their blood molecules. These include:
Anti-nuclear antibody (ANA)
Anti-islet cell antibody
Anti-carbonic anhydrase antibody
Anti-islet cell antibody
For example, one cross-sectional study of 89 women with PCOS and 87 healthy women found that ANA was present in 18.4% of the PCOS patients compared to just 2.29% of the healthy women.¹³
There are biological links between PCOS and a few other autoimmune diseases. Women with PCOS may have an increased risk of developing:
Systemic lupus erythematosus
Type 1 diabetes
Although there are common links between PCOS and autoimmune diseases, it is not currently categorized as an autoimmune disease. It is considered an endocrinopathy or disease of the endocrine system.
Because some causes and biological markers are the same for PCOS and autoimmune diseases, some researchers acknowledge that it may be an autoimmune disease, although further research is needed.
Androgen hormones, at higher levels in women with PCOS, have a role in reducing immunity. One study of women showed a 64% decline in CD8+ T cells. This is important because these T-cells help properly regulate adaptive (acquired) immunity.¹⁴ ¹⁵
The elimination of immune system balance (homeostasis) that’s associated with PCOS may lead to a weakening of immune responses.
Women make up approximately 78% of those affected by an autoimmune disease. There are a few reasons why women make up a significant portion of people with these disorders.
Endocrine hormones affect acquired immunity, and women undergo three endocrinological transitions in their lifetimes: puberty, pregnancy, and menopause. These endocrine transitions have been linked to a higher risk of developing autoimmune diseases.
Female hormones like estrogen and progesterone are also crucial to correct immune responses, and therefore a lack of balance among these hormones may contribute to processes that trigger autoimmunity.
Treatments for autoimmune disease work to address symptoms, help the body fight disease, and assist with containing the autoimmune processes for each condition. They include:
Immunosuppressive medicines to help control the autoimmune responses
Anti-inflammatory drugs to help reduce this common autoimmune disease symptom
Supplements like vitamins and certain hormones, such as thyroid hormone, help build up healthy immunity and fight disease
Blood transfusions for disorders that harm blood components
Targeted drugs specific to different autoimmune disease processes
In addition, new clinical trials for PCOS treatments are forming or underway.
The risk of infertility increases with the development of PCOS due to hormonal imbalances that impact the regular ovulation cycle. In one large cross-sectional study, 72% of women with PCOS also had infertility issues, compared to 16% of women without PCOS. Though common, infertility in people with PCOS is treatable.¹⁶
Because PCOS targets the immune system, the body’s ability to fight disease properly may be reduced. The condition increased the risk of death by 35% in one population study conducted in Finland. Hypertension, migraines, osteoarthritis, fractures, tendonitis, and endometriosis were also diagnosed at greater rates in women with the condition than in those without it.
PCOS has also been linked to increased risk for:
Type 2 diabetes¹⁷
Major cardiovascular events
In addition, the symptoms of PCOS may be debilitating enough to cause mental health issues. The condition has been shown to increase the risk of suicide up to seven times. In addition, depression was found in 40% of women with PCOS compared to 10.4% of women in the US.¹⁸
Polycystic ovarian syndrome (PCOS) and autoimmune diseases share some common potential causes and biological markers, such as the presence of autoantibodies used to help diagnose autoimmune diseases.
PCOS is also linked to increased risk for several known autoimmune diseases, including Hashimoto’s thyroiditis, Graves’ disease, Type 1 diabetes, systemic lupus erythematosus, and psoriasis. However, it is not currently categorized as an autoimmune disease but is considered a disease of the endocrine system.
Autoimmune diseases occur when your acquired (learned) immunity is faulty, sending signals to your immune system to attack your body’s tissues as if they were foreign bodies.
PCOS has several potential underlying causes in common with the underlying causes of autoimmune diseases. In addition, people with PCOS have certain autoantibodies in their blood, which are markers of autoimmune disease. PCOS is also linked with autoimmune diseases such as Hashimoto’s, Type 1 diabetes, and psoriasis.
A polycystic ovarian syndrome is an endocrinopathy or a disease of the endocrine system. It has some biological markers and causes in common with autoimmune diseases, which is why researchers acknowledge that it is a condition that may be in this category of diseases in the future. However, it is not currently considered an autoimmune disease.
Disease development | Johns Hopkins Medicine
PCOS (Polycystic ovary syndrome) and diabetes | Centers for Disease Control and Prevention
Women and depression | Anxiety and Depression Association of America
Acquired immunity | Merck Manual
Autoimmune diseases | NIH: National Institute of Arthritis Musculoskeletal and Skin Disease
Disease development | Johns Hopkins Medicine
Autoimmune diseases | National Institute of Environmental Health Science
Type B insulin resistance | Endocrine Society
Screening and laboratory diagnosis of autoimmune diseases using antinuclear antibody immunofluorescence assay and specific autoantibody testing | American Academy of Family Physician
CD8-positive T cells (2022)
Polycystic ovary syndrome | Office on Women's Health