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Hashimoto’s Thyroiditis Symptoms

By 24th October 2022March 1st, 2023Health Conditions
Hashimoto’s Thyroiditis

What is Hashimoto’s thyroiditis?

Hashimoto’s thyroiditis is an autoimmune condition that impacts the thyroid gland. This is where the body’s immune system starts to attack the thyroid gland. It is the most common thyroid disorder.

In Hashimoto’s thyroiditis, this immune attack on the thyroid gland can reduce how well the thyroid functions. Due to the role of the thyroid in regulating many processes within the body, low levels of thyroid hormones can lead to a wide range of symptoms.

Symptoms of Hashimoto’s thyroiditis include:

  • Fatigue
  • Constipation
  • Hair loss
  • Depression
  • Memory loss
  • Hair loss
  • Hoarse voice
  • Feeling cold [Source: Pubmed]

Hashimoto’s Thyroiditis is estimated to have a general prevalence of 10-12%, with more commonly being seen in women. Approximately 70-80% of the susceptibility to Hashimoto’s thyroiditis is understood to be based on genetics with specific genes found to increase the risk [Source: Pubmed]

The additional factors that contribute to the remaining 20-30% of the risk of Hashimoto’s thyroiditis are understood to be environmental factors. These include various factors such as life stress, dietary patterns, exposure to radiation, environmental toxins and infections.

Several viruses have been associated with Hashimotos. These include:

  • Hepatitis C virus
  • Human parvovirus B19
  • Coxsackie virus
  • Herpes virus [Source: Pubmed]

There are certain risk factors for Hashimoto’s thyroiditis. The risk of Hashimoto’s thyroiditis increases with:

  • Age (risk of Hashimoto’s thyroiditis increases with age)
  • In those with other autoimmune conditions

Autoimmune conditions include:

  • Myasthenia gravis
  • Systemic sclerosis
  • Sjögren’s syndrome
  • Pernicious anaemia
  • Celiac disease [Source: Pubmed]

Can toxins cause Hashimoto’s thyroiditis?

A range of environmental agents have been linked with reduced thyroid function. These can impact the thyroid in various ways.

Common mechanisms of impact include a reduction in the conversion of thyroid hormones, the inhibition of iodine update (which is essential for thyroid hormone production) and the blocking of thyroid receptors.

These environmental toxins include:

  • PCBs – found in coolants and lubricants
  • Organochlorine pesticides – used as pesticides on crops
  • PBDE’s – found in flame retardants
  • BPA – is used in plastic bottles
  • Perchlorate, thiocyanate -used in fertilizers and in smoking
  • Triclosan – found in antibacterial soaps [Source: Pubmed]

How do you know if you have Hashimoto’s thyroiditis?

A diagnosis of Hashimoto’s Thyroiditis is given by a doctor and is based on certain symptoms and tests.

As mentioned, the symptoms of Hashimoto’s thyroiditis can include:

  • Fatigue
  • Constipation
  • Hair loss
  • Depression
  • Memory loss
  • Hair loss
  • Hoarse voice
  • Feeling cold [Source: Pubmed]

If symptoms are present, an initial test into the thyroid glands’ function will be for TSH (thyroid stimulating hormone) and T4 (the main thyroid hormone). A high level of TSH and a low level of T4 indicate that the thyroid is underperforming. This underperformance is termed hypothyroidism [Source: Mayo Clinic].

There are further blood tests that assist with the diagnosis of Hashimoto’s thyroiditis. In particular, the presence of antibodies indicates an autoimmune process. These are the antibodies anti-TPO and anti-Tg. Anti-TPO antibodies are seen in approximately 95% of those with the condition and anti-Tg antibodies in between 60-80% of those with the condition [Source: Pubmed].

An ultrasound may also be performed to help with the diagnosis of Hashimoto’s thyroiditis. This can indicate the condition with the presence of small cysts and the alteration of the texture of the thyroid gland. [Source: Pubmed]

Symptoms of Hashimoto’s thyroiditis

The symptoms of Hashimoto’s thyroiditis are varied and can impact several areas of the body. This is due to the role of thyroid hormones and the ability of these hormones to affect all cells within the body [Source: Science Direct]

These symptoms can include:

  • Hair loss
  • Gut – constipation, ileus and dyspepsia (indigestion)
  • Fat – increased fat deposits
  • Skin issue – dry and cold skin. It may also be yellowish in colour and thickened.
  • Lung – slow breathing, low levels of oxygen in the body
  • Heart – slow heart rate, decreased cardiac-out out
  • Kidney – decreased glomerular filtration rate, decreased free water excretion
  • Liver – increase cholesterol, gallstones
  • Ovaries – menstrual irregularities, menorrhagia (menstrual bleeding that lasts more than 7 days)
  • Muscles – reduce muscle contractility and muscle cramps
  • Bain – poor memory, poor concentration and low mood
  • Voice – thickening of the vocal cords and hoarse voice

While these symptoms can appear in many areas of the body, an underperforming thyroid gland can be the factor that links them all to a common underlying issue [Source: Pubmed, Pubmed]

Symptoms of Hashimoto's thyroiditis

Does Hashimoto’s thyroiditis cause IBS?

Due to the role of the thyroid in supporting muscle function, poor thyroid health can lead to reduced motility of the gut. The reduced motility can then contribute to symptoms, such as dyspepsia, constipation and IBS.

The symptoms of dyspepsia include:

  • Pain or a burning sensation in the stomach after meals
  • Bloating or belching after meals
  • Feeling full very quickly
  • Pain or discomfort in the stomach [Source: MayoClinic]

The muscle contractions within the small intestine help in regulating the microbial balance. However, if these muscle contractions are altered, this may then lead to changes in the microbial balance in the small intestine. This is a reason why an underperforming thyroid gland is considered a risk factor for SIBO due to the slow movement of the muscles in the mall intestine creating an environment that allows more bacteria to flourish.

SIBO stands for small intestinal bacterial overgrowth and is defined by an increase in the bacterial load within the small intestine. SIBO has been indicated to be the underlying cause of symptoms in up to 80% of those with IBS [Source: Pubmed]. This condition has also been reported to be present in up to 50% of those with an underactive thyroid [Source: Pubmed]

Even without digestive symptoms such as bloating, constipation and dyspepsia, imbalances in the gut bacteria can still be present. These imbalances may then further impact the functioning of the thyroid gland.

Does IBS cause thyroid issues?

While it’s not been shown that IBS causes thyroid issues, gut symptoms are very common in those with thyroid conditions. Research has indicated that imbalances in the gut microbiome may contribute to thyroid conditions.

The gut microbiome is the community of microorganisms inside the digestive tract. The is composed of trillions of organisms in the intestines with the highest concentration within the large intestine.

Many factors influence the balance of these organisms. These include:

  • Mode of delivery (e.g. c-section or natural delivery)
  • The mother’s microbiome
  • The use of medications (e.g. antibiotics)
  • Dietary patterns


The gut microbiome contributes to many areas of human health which include its ability to create vitamins, regulate the immune system and support mental health. It has been shown that an imbalanced microbiome can negatively impact the immune system. This can then promote autoimmune conditions such as Hashimoto’s thyroiditis [Source: Pubmed].

One of the ways the gut microbiome impacts the thyroid is through the alteration in the immune response. More than 70% of the human body’s immune system in is the gut which also influences the immune response throughout the entire body [Source: Pubmed]

Imbalances in the gut microbiome, overgrowths of bacteria (as seen in SIBO) and a higher level of inflammation within the gut can impact the thyroid and thyroid function [Source: Pubmed].

Dairy-free diet and Hashimoto’s Thyroiditis

Hashimoto’s Thyroiditis Diet

Certain foods can lead to increased symptoms of Hashimoto’s thyroiditis. When approaching this condition a period of time avoiding certain food or group of foods may help improve symptoms but calming the immune response.

Lactose is a sugar found in dairy products and one study found lactose intolerance to be present in 75.9% of patients with Hashimoto’s. Avoiding lactose from dairy products is important to be aware of when taking the thyroid hormone replacement medication levothyroxine. This is partly due to calcium inhibiting the absorption of levothyroxine by between 20-25% [Source: Pubmed].

It can also be linked to the high incidence of lactose intolerance in those with Hashimoto’s thyroiditis which can impair the absorption of levothyroxine [Source: Pubmed, Pubmed].

Do I need to go gluten-free with Hashimoto’s thyroiditis?

Gluten is highly associated with autoimmune conditions. This is partly due to the cross-reactivity between the gliadin component of gluten and the thyroid. This cross-reactivity is where the immune system sees (and attacks) gluten, but since the structure of the thyroid looks similar, the thyroid also is targeted by the immune system.

Coeliac disease is 10 times more likely in those with autoimmune thyroid conditions when compared to the general population. This can be cause to test for coeliac disease in those with Hashimoto’s disease. However, it is best to test for Coeliac disease before going gluten-free as once gluten has been removed the Coeliac will not be accurate [Source: Pubmed]

Also Read: How To Go Gluten Free

A 2018 study found that a gluten-free diet helped to normalise the levels of thyroid hormones and lower the level of thyroid antibodies. Both indications of a positive effect of a gluten-free diet in Hashimoto’s thyroiditis. It is important that a gluten-free diet is adopted with the support of a practitioner to reduce the risk of nutrient deficiencies [Source: Pubmed].

The cross-reactivity of foods can extend beyond gluten. A 2020 study examined over 200 foods and found many other them have the potential to cross-react with thyroid hormones. For example, buckwheat was found to cross-react with the enzyme that is responsible for converting thyroid hormones into their active form. As buckwheat may be consumed in high amounts when following a gluten-free diet this is particularly noteworthy [Source: Pubmed]

Other foods with the potential to cross-react are:

  • Gluten-containing cereals
  • Seaweed
  • Potatoes
  • Nuts (almonds, cashews, hazelnut, peanut, Brazil nut)
  • Seafood
  • Amaranth
  • Coffee
  • Corn
  • Egg yolks
  • Quinoa
  • Sorghum
  • Tapioca
  • Tofu [Source: Pubmed]

Best Diet for Hashimoto’s Thyroiditis

There is often the need to personalise the diet in those with thyroid and autoimmune conditions. However, there are key nutrients required for thyroid health which can be obtained through the diet.

These vitamins and sources are:

Nutrient Source
Vitamin D Fatty fish (e.g. salmon and sardines), fish oil, sun-dried mushrooms, chicken eggs  
B-Vitamins Meat, fish, chicken eggs, wholegrain cereal products  
Vitamin A Kale, carrot, pumpkin, liver, spinach, egg yolk, butter, dried apricot  
Vitamin C Blackcurrant, kiwi, strawberry, orange, mango, lemon, melon, kale, spinach, tomatoes, peppers (especially red peppers)  
Vitamin E Avocado, fish oil, whole-grain cereal products, vegetable oils  
Magnesium Cocoa and bitter chocolate, pumpkin seeds, avocado, nuts, whole grain cereal products, salmon, green vegetables, yogurt, kefir  
Zinc Cocoa and bitter chocolate, meat, kefir, yogurt, pumpkin seeds, nuts, spinach, mushrooms, whole-grain cereals  
Iron Meat, animal offal, cocoa and bitter chocolate, spinach, sardines, seafood, pumpkin seeds  
Iodine Iodized salt, fish (cod, tuna) and seafood as well as seaweed, iodized milk and dairy products ( if elimination is not required) chicken eggs, plum, especially dried plums, maize  
Selenium Brazilian walnut, fish (sardines, halibut, salmon, tuna), meat, spinach, liver  
[Source: Pubmed]

Gut health and Hypothyroidism

The connection between the thyroid and the gut is called the thyroid-gut axis. The describes the way in which the gut impacts the thyroid as well as the way in which the thyroid may impact the gut. Alterations in this axis may be partly responsible for the development of thyroid symptoms.

Imbalances in the gut microbiome is referred to as dysbiosis and lead to changes within the gut such as:

  • Increased inflammation
  • Reduce immune tolerance
  • Damage to the gut lining
  • Increased intestinal permeability (leaky gut)

The gut can also impact thyroid hormones directly through changes in the enzymes required to produce thyroid hormones as well as inhibiting TSH (thyroid stimulating hormone) [Source: Pubmed].

It is also known that the gut microbiome supports the absorption of nutrients that are required for thyroid function. These include iodine, selenium, zinc and iron and low levels of these has is associated with poor thyroid function therefore imbalances in the gut can impact how we absorb these nutrients [Source: Pubmed].

Imbalances in the gut have been linked to autoimmune processes via several possible mechanisms, all of which influence the immune response and progression. These include:

  • Molecular mimicry
  • Bystander activation
  • Epitope spreading [Source: Pubmed]

Additionally, changes in the lining of the gut have been seen in those with Hashimoto’s thyroiditis, in particular in the duodenum (the first part of the small intestine). These changes included a thickening in the microvilli as well as an increased space between these which may indicate alterations in the structure of the gut wall that may contribute to the local and systemic immune response [Source: Pubmed].

Probiotics for Hypothyroidism

Probiotics are defined as non-pathogenic organisms that when taken in adequate amounts have a beneficial effect on their host. Certain probiotics have been studied in relation to thyroid conditions.

Part of the benefit of how probiotics support thyroid health is via supporting the immune response in the gut, particularly by enhancing the immune cells that regulate the immune system. These are knowns are T-regulatory cells [Source: Pubmed]

An 8-week study using a supplement containing a probiotic and prebiotic (known as a synbiotic) led to an improvement in several areas of thyroid health. This improvement in thyroid health was seen in results such as:

  • Reducing TSH
  • Reducing the dose of thyroid replacement hormone (levothyroxine)
  • Increasing fT3 (free-T3) [Source: Pubmed]

Another study found that certain groups of bacteria in the gut act as a store for thyroid hormones. This means that the appropriate balance of the gut organisms can support thyroid function by supplying thyroid hormones and reducing the fluctuation in levels. This was shown to result in less need for thyroid medications [Source: Pubmed]

Probiotics can also be helpful for Hashimoto’s thyroiditis by their beneficial effect on nutrient levels. This has been seen via their impact on key nutrients required for thyroid function. These include selenium, zinc and copper [Source: Pubmed]

Conclusion

There can be many factors that contribute to thyroid conditions as well as changes in the gut. There are key dietary approaches and supplements that can support the gut microbiome.

These can support the balance of the gut microbiome as well as the immune response and the levels of nutrients required for thyroid health.

Working with a Registered Nutritional Therapist can help support and guide you through the various steps needed to address these issues.