Are Thyroid and PCOS Connected? Experts Weigh In

Irregular periods, infertility, weight gain, fatigue, and depression – these are some of the common symptoms of Polycystic Ovary Syndrome (PCOS) and thyroid. Both these conditions are endocrine disorders and have a strong connection. This article will explain the link between the two, their related complications, as well as lifestyle and prevention tips from experts.

To get a better understanding of this, the editorial team of OnlyMyHealth reached out to Dr Tushar Tayal, Associate Director, Internal Medicine, CK Birla Hospital Gurugram, Dr Vijay Budhwar, Consultant Endocrinologist, Fortis Hospital Jalandhar, and Dr Narendra BS, Lead Consultant, Endocrinology and Diabetology, Aster Whitefield Hospital.

What Is The Connection Between Thyroid and PCOS?

Let us start by understanding the connection between PCOS and thyroid. “PCOS is frequently associated with thyroid problems like hypothyroidism and autoimmune thyroid diseases such as Hashimoto's thyroiditis. Individuals with PCOS have thyroid dysfunctions two to four times more often than those without PCOS,” says Dr Tayal. He lists the similarities or links between both conditions for us:

Hormone Imbalances

The first similarity between the two syndromes lies in hormone imbalances. In hypothyroidism, there is an excess of TRH, causing an excess of prolactin, resulting in menstrual irregularities and ovarian dysfunction, which is seen in women with PCOS. 

Insulin Resistance

Both PCOS and hypothyroidism are associated with insulin resistance; this is critical in PCOS since it results in hyperandrogenism.

Autoimmunity

Another similarity between the two syndromes is autoimmunity. Patients with PCOS tend to have higher autoantibodies against their thyroids.

Obesity

The presence of obesity further emphasises the correlation because it increases insulin resistance and hormone imbalance. 

“In terms of medical practice, undiagnosed hypothyroidism causes worsening of symptoms of PCOS, such as irregular menstrual cycle, infertility, and metabolism. Thus, several treatment regimens advise women suffering from PCOS to regularly examine their thyroid gland,” adds Dr Tayal.

A 2025 study, published in the ‘Clinical Medicine Insights: Endocrinology and Diabetes’ journal, examined 236 women to understand the link between thyroid and PCOS. The findings noted that hypothyroidism (underactive thyroid) is about three times more common in women who have PCOS, than those who haven’t. It added that those who have both PCOS and thyroid, have a higher risk of metabolic issues, high BP or cholesterol levels, diabetes, and heart diseases. 

What Happens When Thyroid and PCOS Co-exist?

When both these conditions co-exist, there are certain health risks they pose. “While their combination is not immediately life-threatening, they pose long-term health risks that can severely impact the quality of life. When they coexist, weight gain becomes much harder to manage because the basal metabolic rate drops. Women with both PCOS and hypothyroidism have a higher association with heart failure and chronic kidney diseases compared to PCOS alone,” explains Dr Budhwar.  

He adds, “Research suggests that women with PCOS have 2.5-3 times higher odds of developing a thyroid disorder; and if thyroid‑stimulating hormone (TSH) levels rise, the risk of type 2 diabetes also increases.”

A 2025 study, published in the ‘European Journal of Medical Research’, examined 124 women. The findings showed that women who had both PCOS and thyroid had higher levels of prolactin (a hormone which enables milk production) and thyroid-related antibodies. The study added that a mildly underactive thyroid may impact specific hormones in PCOS patients, but does not change the core reproductive hormone balance.

Related Complications of Thyroid and PCOS

There are certain complications and risks when both the conditions exist together. Dr Budhwar lists them for us:

• The high insulin resistance in PCOS when getting additional support of deranged thyroid functions, the chances of developing pre-diabetes or type 2 diabetes severely increase.
• This duo often leads to a higher bad cholesterol (LDL) and triglycerides, which can increase the chances of developing cardiovascular diseases.
• Both conditions directly impact the menstrual cycle. This can lead to irregular or heavy periods, missed cycles, or prolonged bleeding that can cause anaemia and fatigue.
• The double imbalance caused by both conditions can make it difficult for the body to release eggs, complicating plans for pregnancy.
• The hormonal imbalance can also cause excess facial or body hair growth and head hair loss.

Can You Prevent Thyroid and PCOS From Occurring Together? 

Dr Budhwar shares that we cannot fully prevent either condition if there is a strong genetic or autoimmune background, but we can reduce the risk and severity by following these:

• Maintaining a healthy weight through regular physical activity and balanced eating helps lower insulin resistance, which is a common link between PCOS and thyroid dysfunction.
• For women already diagnosed with PCOS, periodic thyroid screening (TSH, T3, T4, and anti‑TPO antibodies if there is a deranged thyroid profile) is recommended, especially if fatigue, weight gain, or hair loss become prominent.
• Minimising stress, prioritising sleep, and avoiding a highly processed diet can reduce chronic inflammation and may help delay or soften the onset of thyroid issues or PCOS flare‑ups.

“While it may not always be possible to completely prevent these conditions, especially when there is a genetic predisposition, early lifestyle intervention can significantly reduce the risk and severity,” adds Dr Narendra.

Lifestyle and Diet Tips To Manage Thyroid and PCOS

To effectively manage PCOS and thyroid, Dr Budhwar shares the following lifestyle and dietary tips that may help:

• Aim for at least 150 minutes per week of moderate intensity exercise, such as brisk walking, cycling, or swimming along with yoga; it improves insulin sensitivity and supports thyroid metabolism without overstraining the body.
• Get adequate sleep of 7–8 hours per night; avoid late‑night screens, and incorporate relaxation techniques such as deep breathing or meditation to keep stress hormones under control.
• Avoid smoking, limit alcohol, and reduce very high caffeine intake, because these can worsen hormonal imbalances and metabolic health.
• Minimise refined sugar, white bread, maida‑based products, and packaged snacks.
• Emphasise whole grains (oats, brown rice, and millets), vegetables, salads, and fruits such as berries, apples, and papaya.
• Protein meals such as chickpeas, paneer, tofu, eggs, fish, or chicken can curb hunger spikes and support hormone balance.
• Add thyroid-supportive nutrients in moderation: iodised salt, fish or seafood, and zinc sources such as pumpkin seeds and nuts.
• Use iodised salt, instead of non-iodised, sendha, or pink salt.

Tests To Diagnose Thyroid and PCOS

According to the Cleveland Clinic, doctors diagnose PCOS with the help of the following:

• Knowing about your symptoms and medical history.
• Measuring weight and blood pressure.
• Performing physical exams to check for excess facial hair, hair loss, acne, discoloured skin, and skin tags.
• Performing a pelvic exam to check for abnormal bleeding.
• Blood tests to check your hormone and glucose levels.
• Performing a pelvic ultrasound to check your ovaries, the thickness of your uterine lining, and other causes of abnormal bleeding.

For thyroid diagnosis, Cleveland Clinic suggests the following tests: 

• Blood tests can check for hypothyroidism or hyperthyroidism. There are different types of thyroid blood tests such as thyroid-stimulating hormone (TSH), T3, T4, and thyroid antibodies.
• Imaging tests such as a thyroid ultrasound can help doctors check for nodules (lumps) and/or goitre. Nuclear medicine imaging like a thyroid uptake and scan may also help show if nodules are overactive.

When To Visit a Doctor?

Dr Budhwar shares that you need to seek medical advice promptly if:

• Periods are absent or very irregular (longer than 40 days).
• Someone has been trying to conceive for more than 6-12 months without success.
• If there is unexplained weight gain, persistent fatigue, hair loss, constant feeling of coldness, dry skin, or mood symptoms that interfere with daily life.

"Women already diagnosed with either thyroid disorder or PCOS should seek evaluation, if symptoms worsen or do not improve despite lifestyle changes. Regular follow-ups are important to monitor hormone levels, adjust medications if needed, and prevent long-term complications. Early and coordinated management can significantly improve quality of life and reproductive health outcomes,” adds Dr Narendra. 

Conclusion

In conclusion, thyroid disorders and PCOS have a strong correlation with one another due to their common physiological and metabolic processes. When both these conditions coexist, there are certain health risks they pose. Therefore, it is important to maintain a healthy lifestyle and seek medical help to keep these endocrine disorders in control.