PCOS and Hypothyroidism

PCOS and Hypothyroidism

PCOS and hyporthyroidism
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Dr. Minako Abe
Medically reviewed by

Dr. Minako Abe, M.D., Board-certified emergency medicine physician researching the relationship between lifestyle and disease onset in relation to the immune system and cancer, Japan

Polycystic ovary syndrome (PCOS) is an endocrine disease that affects 15-20% of ovulating women.  Overall, PCOS is caused by an excess of androgens, which are male hormones also produced by females. The condition affects the ovaries and can cause oligo-anovulation or reduced ovulation, irregular periods, and elevated levels of testosterone and dihydrotestosterone (an excess of male hormones). It can also cause severe acne and infertility as it may lead to cysts on the ovaries, otherwise called polycystic ovaries. The disease is most often characterized by irregular or absent menstrual bleeding patterns caused by estrogen influences on the endometrium. This puts patients with PCOS at nearly three times the risk of developing reproductive or endometrial cancers caused by estrogen-induced lesions.

Hypothyroidism is a common condition where your thyroid gland is not producing enough thyroid hormone. With hypothyroidism, the patient may experience severe symptoms including weight gain, fatigue, hair loss, dry skin, muscle cramps, loss of libido, carpal tunnel syndrome, depression, irregular or heavy periods, memory problems, and if left untreated could cause heart failure, psychosis, comas, and death. Hypothyroidism is often caused by iodine deficiency and can appear in both sexes; however, it is 10 times more common in women than in men.

While both conditions affect the patient’s reproductive health and hormonal balance, PCOS is mainly caused by insulin resistance that increases androgen levels and genetic factors that suggest autosomal transmission where the ovary becomes more susceptible to androgen secretion. This means mothers can pass on PCOS to their daughters by exposing them to hormone disruptors, insulin, and androgens while in the womb. Causes of hypothyroidism include chronic autoimmune thyroid disease, iodine deficiency, and the thyroid not producing enough thyroid hormones such as thyroxine (T4) and triiodothyronine (T3). Moreover, symptoms such as weight gain, irregular periods, and fatigue may  also increase the risk of miscarriage and complications during pregnancy. PCOS and hypothyroidism often occur together in female patients making the discussion around the link behind both diseases vital for diagnosis, treatment, and improving overall patient care.

What Causes PCOS and/or Hypothyroidism?

Alongside similar symptoms, both diseases are intertwined in what causes them. Hypothyroidism is a common thyroid disorder in women of reproductive age. Thyroid hormones are needed to properly stimulate the development and metabolism of the ovaries and uterine, so disruptions in hormone production can cause reproductive disorders like delays in the first menstrual cycles, interruptions in puberty, ovarian cysts, anovulation (the ovaries don’t release an egg or a menstrual cycle without ovulation), and irregularities in the menstrual cycle.

Hypothyroidism also causes reduced glucose production, leading to insulin resistance, a major cause of PCOS. There is growing evidence that suggests PCOS increases the risk of developing hypothyroidism and other thyroid diseases such as nodular goiter and autoimmune thyroiditis. One study found that thyroid-stimulating hormones (TSH) were significantly higher in PCOS patients. They also concluded that obesity and insulin resistance were major links between the two diseases. In fact, patients with hypothyroidism were found to have a greater metabolic risk of obesity, insulin resistance, and hyperlipidemia which was also seen in PCOS patients.

Next, hypothyroidism can compromise the immune system by causing autoimmune thyroiditis. When the immune system is weakened, the anti-inflammatory mechanism is reduced. In PCOS, estrogen stimulates the immune system but anti-inflammatory procedures from normal progesterone levels neutralize this. Unfortunately, with PCOS, progesterone levels are extremely low  due to anovulatory cycles, where an egg isn’t released from the ovaries during ovulation. The consequence of very low progesterone is that estrogen over-stimulates the immune system causing it to become overactive. This is what is often seen in autoimmune diseases, where the immune system begins to attack normal cells while in overdrive. In other words, PCOS is capable of increasing the incidence of autoimmune disorders like hypothyroidism.


  • An Eastern Indian study found that 22.5% of women with PCOS also had hypothyroidism compared to 8.75% of those who did not have PCOS.
  • In 2015, the National Institutes of Health found that 22.1% of PCOS patients had Hashimoto’s thyroiditis compared to 5% of patients without PCOS.
  • Another study found that 46.8% of girls with euthyroid chronic lymphocytic thyroiditis (CLT) also had PCOS compared to 4.3% of non-CLT control patients.
  • A Turkish study showed that the prevalence of Hashimoto’s thyroiditis in PCOS patients was significantly high at 38.18%.
  • A study from 2013 found that infertile PCOS patients had a higher level of antithyroid antibodies and subclinical thyroid dysfunction than infertile non-PCOS patients.

Environmental Factors

In addition to genetics, environmental risk factors play a role in increasing a person’s susceptibility to both conditions. Factors such as an unhealthy diet, sedentary lifestyle, and biochemical disruptions are all considered but the specific triggers of each condition are different. For example, evidence suggests that exposure to endocrine/hormonal disrupting chemicals like bisphenol A (BPA), found in plastic products like food storage containers, can increase the risk of PCOS.

Many of these chemicals have estrogenic or androgenic properties that impact a patient’s hormone levels and production. Diet is a major environmental determinant of PCOS as obesity can increase insulin resistance. Additionally, hypothyroidism is linked to iodine deficiency which can be caused by a lack of dietary intake or exposure to radiation such as medical radiation from x-rays or radiation from nuclear fallout. For example, antithyroid antibodies, which target and damage specific parts of the thyroid, were found to have increased in children 6 to 8 years after being exposed to radioactive fallout from the Chernobyl accident.

Therefore, while both PCOS and hypothyroidism have environmental risk factors that can worsen the symptoms, they have different triggers. Individuals with either condition need to be aware of these environmental risk factors to ensure they can reduce their impact on their health.

Diagnosis: Both Conditions Affect a Patient’s Hormonal Balance

Both conditions are often misdiagnosed or overlooked due to their similar symptoms and because of the association between insulin resistance and reproductive disorder. This means that patients with hypothyroidism are often excluded from a PCOS diagnosis. The criterion for diagnosing PCOS includes looking for clinical or biochemical hyperandrogenism (high levels of androgen hormones), oligo/amenorrhea anovulation, and polycystic ovarian symptoms. These signs are often examined using ultrasounds of the ovaries and hormone blood tests.

On the other hand, hypothyroidism is confirmed when serum thyrotropin (TSH) levels are high meaning there is a low amount of thyroid hormones being produced. TSH concentrations in hypothyroidism are typically above the normal range of 0.4 – 4.0 mIU/L. Blood tests can be used to measure thyroid hormone levels and free thyroxine concentrations. Women experiencing symptoms of either disease must seek medical attention from their healthcare provider to receive a proper diagnosis followed by treatment options.

Diagnosis Criteria



  1. Clinical or biochemical hyperandrogenism (high levels of androgen hormones)
  2. Oligo-anovulation
  3. Polycystic-appearing ovarian morphology on ultrasound
  4. Exclusion of other reproductive disorders
  1. TSH levels above  0.4 – 4.0 mIU/L.
  2. Measuring free thyroxine if TSH is elevated.

Treatment Options: Medication vs. Lifestyle Changes

Between both diseases, improving the body’s insulin sensitivity through pharmacological and lifestyle interventions are recommended for treatment. By doing so, there is the potential to restore ovulation, decrease abnormalities in the reproductive cycle, and prevent infertility or pregnancy complications. One study found that using insulin-sensitizing medications and medications like metformin and inositol significantly reduced TSH levels in PCOS patients.

 Lifestyle changes are a non-pharmaceutical treatment option.


1. Use allergen-free alternatives

Allergies are autoimmune reactions, and autoimmune disorders are known to affect the thyroid gland. Graves’ disease and Hashimoto’s thyroiditis are both examples of autoimmune thyroid diseases. Moreover, thyroid autoantibodies, an antibody that directly destroys cells, increase the risk of allergic diseases.

2. Add more anti-inflammatory foods

  • Leafy Greens
    • Spinach, lettuce, or  kale
  • Nuts
    • Cashews, almonds, or pumpkin seeds
  • Seafood
  • Salmon, tuna, seaweed, or shrimp
  • Fruits
  • Blueberries, blackberries, strawberries, or oranges

3. Incorporate high-fiber and protein-rich foods while avoiding sugary and processed desserts and junk food


Maintaining a Healthy Weight

1. Exercising can help improve your insulin sensitivity and metabolism

2. Exercise can also reduce testosterone levels, improve hair growth, and reduce body fat.


Stress Management

1. Yoga and meditation can help alleviate symptoms as stress can increase insulin resistance, weight gain, and inflammation.

2. Getting 8 hours of sleep nightly


Overall, addressing hormone issues through medication or lifestyle changes such as diet, stress management, and exercise can help alleviate symptoms associated with PCOS and hypothyroidism.

Key Takeaways

  • Polycystic Ovary Syndrome (PCOS) and Hypothyroidism are two common endocrine disorders that affect menstruating patients.
  • One of the most common symptoms shared by both conditions is weight gain due to insulin resistance.
  • Both conditions share many symptoms like weight gain, irregular periods, and fatigue while increasing the risk of miscarriage and complications during pregnancy.
  • PCOS is diagnosed with blood tests to measure hormone levels, including testosterone and insulin, and an ultrasound to check for cysts on the ovaries.
  • Hypothyroidism is diagnosed through a blood test that measures thyroid hormone levels.


The link between PCOS (Polycystic Ovary Syndrome) and hypothyroidism lies in their shared impact on hormonal balance within the body. Both conditions can affect hormone levels, potentially leading to disruptions in menstrual cycles, fertility issues, and other related symptoms.

Hypothyroidism can exacerbate symptoms associated with PCOS, such as irregular periods, weight gain, and fertility challenges. Thyroid hormone imbalances may contribute to hormonal irregularities, amplifying the hormonal imbalances already present in PCOS.

Seeking guidance from healthcare professionals, including endocrinologists, gynecologists, and registered dietitians, is crucial for effectively managing PCOS and hypothyroidism together. These experts can provide personalized treatment plans, dietary recommendations, and ongoing support to address the complex interplay between these two conditions and optimize overall health outcomes.


At ThyForLife, we do our utmost to provide accurate information. For detailed medical information regarding diagnosis, treatment, and general practices please consult your healthcare professional. Always listen to the advice of your healthcare provider.
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