Dr. Vinu Jyothi, MD, MPH and Senthil Samy, PhD
PCOS (polycystic ovary syndrome) and hypothyroidism (underactive thyroid gland) are two of the most prevalent endocrine disorders affecting women. PCOS affects between 5% and 10%, making it one of the most common endocrine disorders in women. Yet, it’s estimated that 50 to 75 percent of people with PCOS don’t know they have it, according to a 2018 study . Whereas, hypothyroidism affects between 6% and 8% of women of reproductive age [2, 3]. It may come as a surprise, but there’s a growing consensus in the medical community that hypothyroidism and PCOS are closely linked [4, 5]. There are many overlapping characteristics between PCOS and hypothyroidism. Understanding the similarities and differences between hypothyroidism and PCOS — and having the right tools to aid in evaluation — can lead to an accurate diagnosis and inform optimal treatment decisions.
The symptoms of hypothyroidism usually develop slowly over time – sometimes years. Women battling hypothyroidism generally feel more tired and sluggish and are at risk of developing PCOS.
Other symptoms include:
• Experiencing numbness and tingling in your hands.
• Having constipation.
• Gaining weight.
• Experiencing soreness throughout your body [can include muscle weakness].
• Having higher than normal blood cholesterol levels.
• Feeling depressed.
• Being unable to tolerate cold temperatures.
• Having dry, coarse skin and hair.
• Experiencing a decreased sexual interest.
• Having frequent and heavy menstrual periods.
• Seeing physical changes in your face (including drooping eyelids, and puffiness in the eyes and face).
• Having your voice becomes lower and hoarser.
• Feeling more forgetful (“brain fog”).
This thyroid condition is one that women with PCOS are especially susceptible to. Hashimoto’s is best described as an autoimmune condition in which the immune system does not recognize the thyroid gland as part of its body system, but rather mistakenly attacks the thyroid gland . This misguided attack on the thyroid gland impairs the production of thyroid hormone causing symptoms like fatigue, weight gain, hair loss, and irregular menstrual cycles.
Hashimoto’s disease symptoms
People may be asymptomatic in the early stage, but they may develop the following symptoms as the condition progresses:
- Weight gain
- Slowed heart rate
- Heavy or abnormal menstrual periods
- Sensitive to cold
- Puffiness of face
- Difficulty to conceive
- Dry skin
- Enlargement of the thyroid gland
The link between hypothyroidism and PCOS
While the link between hypothyroidism and PCOS remains complex, the latest research shed some light. It is evident that women with PCOS are associated with a high incidence of a thyroid disorder as compared to their normal counterparts with nearly a quarter of the women with PCOS having hypothyroidism. More specifically, women with PCOS are three times more likely to also suffer Hashimoto’s Thyroiditis, a certain type of hypothyroidism, than the general population [3, 4].
Apart from coexistence possibilities in women, PCOS and hypothyroidism also share many common features . The common signs and symptoms include—inflammation, androgen overload, insulin resistance, toxic liver, disturbances in cortisol levels, and blood sugar problems. Even though PCOS and hypothyroidism have different disease origins, they also have many similarities. While overlapping features between these two conditions suggest a potential link, scientists aren’t quite sure how these two conditions are related and the exact nature of the relationship is not fully understood. Let’s take a closer look at the mutual but complex relationship between PCOS and hypothyroidism.
Hormonal balance and Ovarian Health
The study also revealed that women with PCOS had greater levels of testosterone (androgen overload) that impact the functioning of ovaries. As a consequence, severe and longstanding hypothyroidism not only increases the volume of ovaries but also contributes to cyst formation, as well as other symptoms such as extra hair growth, acne, and weight gain . Whereas, hypothyroid women often suffer from menstrual problems and fertility issues. Recent studies have shown that women with hypothyroidism, had significantly larger ovaries, thus suggesting that thyroid dysfunction has a large impact on the ovarian size and might produce ovarian cysts.
Insulin resistance is correlated to obesity which is common for both hypothyroidism and PCOS. Insulin resistance is a condition wherein our body fails to respond to insulin that helps our body to manage glucose. The reason behind this relationship is that thyroid dysfunction impairs glucose metabolism  through multiple mechanisms including increased inflammation, oxidative stress, and mitochondrial dysfunction. Increased insulin resistance leads to type 2 diabetes. A study published in Lancet indicates that about 70% of people with insulin resistance will develop type 2 diabetes if they don’t change their lifestyle . This also leads to an increased risk of cardiovascular events.
Being overweight and obesity are the common symptoms of both PCOS and hypothyroidism. Weight gain is one of the most common symptoms of the underactive thyroid gland[11, 12]. Weight gain in hypothyroidism occurs due to several factors. Given that both PCOS and hypothyroidism are associated with overweight/obesity and higher BMI, it’s apparent that both conditions are connected on a deeper level [11,12].
Differential diagnosis and treatment approaches for hypothyroidism and PCOS
The overlapping symptoms and the lack of diagnosing criteria for PCOS and hypothyroidism together have led the experts to misdiagnose both disorders. The fairly complex relationship between these two conditions remains to be fully understood. Regardless, women with polycystic ovaries should have their thyroid evaluated and the same goes for women diagnosed with hypothyroidism. You may want to consult your healthcare provider to see whether everything is okay with your ovaries and whether you could be at risk of developing PCOS. Due to the impact of thyroid function on ovaries, a proper evaluation requires clinicians to exclude or confirm the possibility of hypothyroidism before making a definitive diagnosis of PCOS. This is particularly important if you’re a woman trying to get pregnant or already conceived.
Given that these two conditions have different causal factors, clinical diagnosis and treatment of each condition can vary based on symptoms and blood tests.
The symptoms of hypothyroidism often vary among different people and may be difficult to identify at an early stage. The severity of the condition also affects which signs and symptoms appear and when.
Women with hypothyroidism may not realize that these changes are related to the thyroid until more symptoms appear. For most people, symptoms of the condition progress gradually over many years. As the thyroid slows more and more, the symptoms may become more easily identified. Given the latest advancements, now it is easier to measure the levels of TSH (thyroid-stimulating hormone) and thyroxine (thyroid hormone). Treatment of hypothyroidism often involves the use of synthetic thyroid hormone which can restore hormone levels and help to reverse the symptoms associated with the condition. However, some people don’t feel great while on either synthetic or natural thyroid hormone and they are told to take thyroid hormone for the rest of their life,
When it comes to PCOS or polycystic ovary syndrome, the diagnosis involves a review of medical history, PCOS symptoms, blood tests, and as well as a vaginal ultrasound to check the patient’s reproductive system. Also, to rule out hypothyroidism in women with PCOS, thyroid function tests are recommended, along with glucose tests and lipid level tests to assess cholesterol. Therapeutic approaches for PCOS focus on managing the symptoms and helping the patient avoid any complications. A healthy and PCOS-friendly diet and exercise is highly recommended, especially if obesity is an issue as weight loss can help to regulate the menstrual cycle and maintain glucose level. The anti-androgen approaches can help stop excess hair and reduce acne.
However, it seems that these are two separate ailments with their features and, therefore, have to be considered independently as well when a person complains about symptoms. Some medical experts started to believe that more attention can shed light on the relationship between the two conditions, as PCOS hypothyroidism could be a phenomenon to be explored collectively for developing future strategies.
Essential Supplements for Healthy Thyroid Function
Some dietary supplements may help reduce hypothyroidism symptoms. Typically, thyroid supplements including the following are proven extremely beneficial in maintaining the optimum functioning of the gland and improving both physical health and emotional stability.
- Iodine: Iodine deficiency is the most common cause of goiters — an enlarged thyroid. Iodine seems to be important in treating and preventing autoimmune disorders, such as Hashimoto’s thyroiditis.
- Selenium: Research indicates that selenium, when added to conventional treatment of hypothyroidism, improves thyroid function.
- Vitamin D is essential to thyroid function. Vitamin D deficiency can lead to Hashimoto’s disease and hypothyroidism. Our greatest source of Vitamin D comes from sunlight exposure. For high medical-grade, 3rd party-tested Vitamin D, check out our PCOS Diva shop
- Zinc helps convert T4 to T3, important to preventing thyroid disorders. Healthy zinc intake leads to higher T3 levels. You can get dietary zinc from meats, shellfish, and mollusks. For high medical-grade, 3rd party-tested Zinc is available at our PCOS Diva shop.
- Probiotics Dietary probiotics can help restore normal thyroid function. Studies show that probiotics can reverse leaky gut by strengthening the lining of your intestines. Shop our PCOS Diva for probiotics
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