Learn about the connection between polycystic ovarian syndrome (PCOS) and hypothyroidism.

In this article:

  • What is PCOS?
  • How is it diagnosed?
  • Understanding the link between PCOS and hypothyroidism
  • How to manage when you have both conditions

People with polycystic ovarian syndrome (PCOS) are at increased risk of having other hormonal imbalance conditions, including hypothyroidism. Both PCOS and hypothyroidism share many similarities in symptoms and effects on the body. Unfortunately, women with both conditions can go undiagnosed for many years until the symptoms become too overwhelming or other issues arise. An early diagnosis of PCOS and hypothyroidism can reduce your risk for other health conditions and improve your overall health and quality of life.

What is polycystic ovarian syndrome (PCOS)?

Polycystic ovarian syndrome is a hormonal disorder that disrupts sex hormones in women of reproductive age. Currently, between 5-10% of women of reproductive age globally have PCOS. We do not know of the exact cause of PCOS, but women with PCOS tend to have excess androgen levels (male sex hormones) that cause the following symptoms:

  • Infrequent, prolonged, or irregular menstrual periods
  • Hirsutism (excess facial and body hair growth as a result of high androgen levels)
  • Hormonal acne
  • Male-pattern hair loss
  • Polycystic ovaries (the ovaries can become enlarged, and cysts can form around the eggs)
  • Infertility
  • Excess weight gain or obesity
  • Metabolic syndrome

Again, while the exact cause of PCOS is unknown, some leading theories may explain this disorder. 

Excess insulin

Excess insulin may play a role in PCOS. Insulin is a hormone produced in the pancreas that helps cells use glucose from food for energy instead of stored energy. Too much glucose (or blood sugar) can cause your body to produce more insulin, which in turn may increase androgen production. This relationship may explain why people with PCOS often struggle with metabolic syndrome and weight gain.

Family history

Family history likely influences PCOS as it tends to run in families. Recent research has found that specific genes may affect the production of sex hormones. However, no single gene sequence is responsible for PCOS as of yet.  


Chronic inflammation may stimulate the ovaries to produce more androgens. We know that inflammation is a crucial component of autoimmune disorders, which disproportionately affects women.

How is PCOS diagnosed?

There is no specific test used to diagnose PCOS. Typically, your doctor will review your medical and family history and will want to know about any irregularities in your period and changes in your weight. A physical exam will be necessary to look for signs of hirsutism and acne, and you will likely have a pelvic exam.

Sometimes, your doctor may order additional tests. For example, you may need a blood test to measure your hormone levels, blood glucose, and cholesterol. An ultrasound of your ovaries can help your doctor see cysts or other abnormalities that may be impacting your periods or fertility. 

Understanding the link between PCOS and hypothyroidism

Women who have PCOS commonly have Hashimoto’s thyroiditis, too. One study found that women with PCOS were three times more likely to have Hashimoto’s than women who did not have PCOS. 

Hashimoto’s is an autoimmune disease and is the leading cause of hypothyroidism. In Hashimoto’s, the immune system mistakenly attacks a healthy thyroid gland, which causes inflammation. Over time, this inflammation can cause the thyroid gland to stop working, consequently lowering your body’s thyroid hormone levels.

Interestingly, people with PCOS and hypothyroidism tend to have lower androgen levels and signs of excess androgen than people with PCOS who do not have hypothyroidism. A plausible theory is that low thyroid hormone production suppresses androgen production. However, people with both conditions are more likely to suffer from metabolic complications like weight gain and obesity.

How to manage when you have both conditions

Early diagnosis

People with PCOS and Hashimoto’s are at a greater risk for poor cardiovascular and reproductive outcomes than those who only have PCOS. Therefore, it is imperative to get a diagnosis for these conditions as early as possible. If you are diagnosed with PCOS, it is helpful to ask your doctor to check your thyroid function.

Take your medication

If you have both PCOS and hypothyroidism, it is crucial to take your thyroid hormone replacement medication. Make sure to take your medication as prescribed and avoid doing things that can affect your thyroid medication, like taking it with food.  

Reduce inflammation

Certain things can increase inflammation and may worsen your thyroid symptoms. Try to eat clean, healthy foods, or consider trying the autoimmune protocol diet (AIP). Reducing stress on your body and mind can also decrease inflammation. 

Track your menstrual periods

Your periods can be a great way of assessing if you are on a suitable treatment plan. Suppose your periods are still irregular after using thyroid medication for several months. In that case, it is helpful to follow up with your doctor. 

Improve your gut health

More and more, research is pointing to the importance of a healthy gut microbiome. When there is an imbalance in your gut microbiota, it can cause inflammation and aggravate your immune system. Furthermore, the gut helps balance sex hormones like estrogen. 

Balance blood sugar

Blood sugar imbalance occurs in both PCOS and hypothyroidism. It is necessary to monitor your carbohydrate and refined sugar intake to reduce your risk for insulin resistance and metabolic syndrome.

Medication for PCOS

There are several approaches to managing PCOS, and treatment depends mainly on your symptoms. For example, some women may be prescribed birth control pills to help regulate the menstrual period and improve hirsutism and acne. Some medications, like clomiphene, help you ovulate when you are seeking infertility treatment. Additionally, you may need a prescription to help with metabolic syndrome, like metformin. 

Control your weight

Even slight reductions in your weight can have remarkable benefits for your thyroid and PCOS symptoms. Aim to exercise regularly to help with weight loss and boost your energy.