If you’ve been reading #AskEvvy for a while now, you’ve likely learned that your vaginal health can be affected by many other organs and body systems. These include the glands of your endocrine system, including your thyroid gland. 

Read on to learn about the roles of this little organ and how it can wreak havoc on your health when it goes haywire.

What does the thyroid do?

The thyroid gland is a small gland located at the base of the throat. It’s present in people of all sexes. The thyroid releases hormones into the bloodstream. These chemicals help drive growth and development, regulate metabolism, and control heart rate.

Like any other organ in the body, the thyroid can develop problems. Hypothyroidism is a common thyroid condition that results in lower-than-normal levels of thyroid hormones (known as T4 and T3) in the bloodstream.

Approximately 5% of the world’s population has diagnosed hypothyroidism, and researchers estimate that an additional 5% has the condition but remains undiagnosed.

What causes hypothyroidism? 

The vast majority (>99% of cases) of hypothyroidism results from underproduction of thyroid hormones by the thyroid gland. Hypothyroidism can occur for a variety of reasons, but one reason is that the thyroid depends on the chemical iodine to make its hormones, so a deficiency in dietary intake of iodine can lead to hypothyroidism. 

This is less common in areas of the world where dietary iodine levels are sufficient—and yes, this is exactly why your table salt is iodized!

In other cases, hypothyroidism is due to an autoimmune condition called Hashimoto’s thyroiditis. Hashimoto’s causes the body’s immune system to attack the cells of the thyroid, causing chronic inflammation and dysfunction of the gland.

What are the symptoms of hypothyroidism?

Regardless of cause, hypothyroidism results in a wide variety of symptoms affecting physical, metabolic, sexual, and psychological functioning. 

Here are a few of the most common in each category:
Physical

  • Hoarse voice
  • General muscle soreness and achiness
  • Dry skin/hair and brittle nails
  • Hair loss
  • Constipation
  • Goiter (A goiter is a lump in the throat due to an enlarged thyroid gland. It’s a rare symptom, but it is a key sign of thyroid problems.)

Metabolic

  • Fatigue
  • Weight gain
  • Intolerance to cold

Reproductive/Sexual

  • Delayed onset of puberty
  • Irregular periods
  • Frequent, heavy vaginal bleeding
  • Sexual dysfunction
  • Impaired fertility

Psychological

  • Difficulty concentrating
  • Memory problems
  • Depression

How is hypothyroidism diagnosed?

Symptoms alone aren’t enough to confirm a diagnosis of hypothyroidism – so even if some of the symptoms listed above sound familiar, don’t panic. If you suspect you may have hypothyroidism, start by talking with your primary care provider or another healthcare provider you trust. 

Your provider can order a blood test to check your circulating levels of thyroid hormones: this will allow them to confirm or deny the presence of a thyroid disorder. Fortunately, even if you are diagnosed with hypothyroidism, there are safe, effective treatments for the condition. The most commonly prescribed medication for hypothyroidism is levothyroxine (the generic form of Synthroid®).

The Neck Bone’s Connected to the…Vagina?

Even if you understand that various body systems can impact your vaginal health, it might not be immediately obvious that a tiny gland in your neck can have far-reaching effects on your nether regions. Hypothyroidism can impact multiple aspects of vaginal and gynecologic health, including sexual function, menstrual cycles, and possibly even the vaginal microbiome. Let’s consider what we know in each of these domains.

How does hypothyroidism affect sexual function?

Sexual desire, arousal, satisfaction, pain and orgasm are all suppressed in women with hypothyroidism  Although “sexual dysfunction” is a formal medical term, it can sound more like victim blaming than we’d like. Keep in mind that a wide variety of symptoms fall under the umbrella of sexual dysfunction, including low libido, decreased vaginal lubrication levels, lower rates of orgasm, and pain during intercourse. 

If you experience any of these symptoms, know that none of them are your fault. They often arise as the side effects of common medical conditions, and they definitely do not mean that you are “broken” or that “something is wrong with you”.  Thankfully, these symptoms can often be addressed! 

These sexual challenges affect an estimated 22 to 46% of women with hypothyroidism. Sexual medicine experts have noted that even “mild” thyroid disruption can negatively impact sexual function in people without formally diagnosed hypothyroidism. 

Fortunately, a variety of medical and mental health interventions exist to help people experiencing difficulties with their sexual function - there is always hope and the opportunity to improve!

How does hypothyroidism impact the menstrual cycle?

Since the 1950s, gynecologic researchers have noted differences in the menstrual cycles of people with hypothyroidism compared to their peers without the condition. Unfortunately, though perhaps unsurprisingly, the gender health gap means that our current understanding of these differences is still in its infancy.

A 2018 study of 86 women without hypothyroidism noted “subtle differences” in the menstrual cycles of these women depending on their levels of circulating thyroid hormones. These data suggest that low thyroid hormone levels could impact the menstrual cycle. However, the findings are not sufficient to draw firm conclusions about menstrual irregularities in people with hypothyroidism.

How does hypothyroidism affect the vaginal microbiome?

To better understand the relationship between the thyroid and the vaginal microbiome, it’s helpful to familiarize yourself with the following:

  1. Thyroid hormones and estrogen (another hormone) affect each other.  
  2. Estrogen affects the vaginal microbiome.
  3. People with hypothyroidism commonly report sexual and other vaginal symptoms (see above).

Given these interconnections, it seems likely and logical that hypothyroidism could impact the vaginal microbiomes of people with the condition. But to the best of our knowledge, there isn’t yet a peer-reviewed research study comparing the vaginal microbiomes of people with and without hypothyroidism. The gender health gap strikes again! 

This is why we can’t yet definitively say whether having hypothyroidism may increase your susceptibility to yeast infections, bacterial vaginosis (BV), and/or other vaginal conditions.

If you suspect that your hypothyroidism may be contributing to vaginal symptoms or disruptions in your vaginal microbiome, it’s not in your head. We just don’t yet have the data or the research to give you a definitive answer. 

This is a big reason why Evvy exists: with your help, we’re working hard to close these and other knowledge gaps for all people with vaginal anatomy. 

In the meantime, if you have hypothyroidism, you can take proactive steps to protect your vaginal health with the Evvy Vaginal Health Test.

Evvy tests for all bacteria and fungi of the vaginal microbiome, supporting you with information about your unique microbiome and any emerging research about its relationship to other conditions. 

As an Evvy Member, you can use our trends and insights tool to track changes in your vaginal microbiome over time. This allows you to see the impact of any changes to your routine or treatment approach to determine what works best for you and your body.

Recurrent symptoms? Get Evvy's at-home vaginal microbiome test, designed by leading OB-GYNs.
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Can a Pill Fix My Vaginal Symptoms from Hypothyroidism?

As nice as a magic bullet for all symptoms of hypothyroidism would be, we can’t yet say for sure whether medications like levothyroxine can resolve the gynecologic effects of the condition. Research on this topic is still frustratingly scarce. 

We believe in treating everyone in our community like they’re smart (because they are), so here’s what we do know: 

Levothyroxine and sexual dysfunction 

As we stated above, an estimated 22 to 46% of women with hypothyroidism experience sexual challenges like impairments in desire, arousal/lubrication, orgasm, satisfaction, and pain during intercourse. Some evidence suggests that medications like levothyroxine can alleviate some of these symptoms, but the data is mixed. 

A study published in 2020 examined the impact of levothyroxine medication on the sexual symptoms of 152 women with hypothyroidism. While these women reported improvements with other hypothyroid symptoms, they still exhibited significantly higher rates of sexual dysfunction than their peers without hypothyroidism. 

But there is evidence that treatment provides some relief to sexual dysfunction symptoms. A study in 2011 found that women who had levothyroxine treatment reported improvements in sexual desire, arousal/lubrication, satisfaction, and pain. But there were still impairments with orgasm and sexual desire.

These findings are consistent with the results of the research related to sexual challenges and hypothyroidism we discussed above. 

While we wish these results provided more definitive insights, it’s important to recall that We still don’t have enough data to definitely determine whether or not levothyroxine can reduce sexual dysfunction associated with hypothyroidism.

Levothyroxine and menstruation

The research on levothyroxine’s impact on menstruation is also lacking. 

However, this study was also small, isolated, and only studied women without hypothyroidism (what?!). These limitations make it difficult to draw broader conclusions about the efficacy of levothyroxine for people with menstrual problems due to known hypothyroidism.

Here we reach an all-too-familiar conclusion: at this time, we simply don’t have enough data to say whether or not the current medical treatments for hypothyroidism will adequately address the sexual and gynecologic symptoms of the condition. 

If you are living with hypothyroidism and experiencing sexual, menstrual, and/or other vaginal symptoms, you are not alone. A good first step is to reach out to a healthcare provider for help and personalized treatment recommendations. We know that discussing these types of symptoms with healthcare professionals can be challenging and sometimes embarrassing, and we’re here to help. Our guide to talking to your provider about vaginal infections is great resource when preparing for these conversations 

If you don’t have access to a healthcare provider near you, you can also try looking into companies like Paloma Health, which offer digital support for hypothyroidism. 

If you live with hypothyroidism and its gynecologic side effects, you’re part of a large community of people living with conditions that predominantly affect folks with female anatomy. At Evvy, we’re on a mission to close the gender health gap and better understand conditions like these. Helping people with hypothyroidism better understand their vaginal health is an important piece of the puzzle. After all, the female body, no matter its condition, shouldn’t be a medical mystery.

This article was written by Meagan Hamblin & Caitlyn Tivy, PT, DPT, OCS.