Is Hashimoto’s Disease Serious?

Hashimoto's disease is an autoimmune disorder and the largest cause of under-active thyroid (hypothyroidism) in the United States. While the exact number experiencing this condition is unknown, it is estimated to be about 1% - 2%¹ of the entire American population.

If Hashimoto’s goes untreated, it can become severe and lead to several complications. These complications may include heart problems or myxoedema coma, a rare condition in which the body’s functions slow down to a dangerous level.

With early diagnosis, treatment, and no other underlying complications, Hashimoto's disease is not serious for most people.

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What is Hashimoto's disease?

Hashimoto's disease, also known as chronic lymphocytic thyroiditis, is an autoimmune disease that gradually affects the thyroid gland. The butterfly-shaped thyroid gland is a vital organ since it generates hormones responsible for regulating the body's metabolism, development, growth, mood, and other functions.

The exact cause of Hashimoto’s disease is still unknown, but it is believed to result from environmental and genetic factors.

The condition occurs when white blood cells accumulate in the thyroid gland, creating antibodies that attack and destroy the gland's cells. Once a number of thyroid cells have been damaged or killed, the gland can no longer produce hormones required to regulate body functions.

Lack of thyroid hormones is usually a sign that you might be suffering from Hashimoto's disease.

Risk factors

Several inherited genes are associated with Hashimoto's disease, the most common of which are HLA-DR5 and HLA-DR3.

These genes are prevalent among people of European ancestry, but their presence does not ultimately mean a person will develop Hashimoto’s. It just means that the person is at a higher risk.

Some autoimmune diseases also increase the risk of developing Hashimoto's disease, including type 1 diabetes, celiac disease, and alopecia areata (autoimmune-related hair loss).

Lifestyle factors such as stress and smoking can contribute to the development of Hashimoto’s. Additional lifestyle factors that may contribute include lack of activity or sleep, nutritional deficiencies, and a low-calorie diet.

Hashimoto’s is more prevalent in females than males. As you age, the risk of developing Hashimoto’s disease is higher; during menopause, low estrogen levels could further affect thyroid function.


The thyroid gland usually enlarges in the early stages of Hashimoto’s disease. However, as the disease progresses, the thyroid reduces in size, resulting in fibrosis and scarring. This is due to the destruction of thyroid tissue and white cell invasion.

Symptoms for Hashimoto's disease often vary and appear gradually, making it easy to overlook or confuse the symptoms with another condition. The most noticeable sign is goiter, a condition in which your thyroid gland becomes enlarged.

Here are some additional common symptoms associated with Hashimoto's disease:

How is Hashimoto's disease diagnosed at the hospital?

The health practitioner starts by checking your medical history and conducting a physical exam while interviewing you about your symptoms.

To determine whether hypothyroidism is the cause of the symptoms, the clinician will order a blood test that could include testing thyroid function through T4 and TSH tests.

Thyroid-stimulating hormone (TSH) is produced in the pituitary gland. If this gland detects low thyroid hormones in the blood, it sends TSH to the thyroid gland to try and increase thyroid hormone production.

High levels of TSH in the blood indicate hypothyroidism. Thyroxine (T4) is the primary thyroid hormone and is low in the case of Hashimoto’s disease.

Since many conditions lead to hypothyroidism, the clinician could request additional antibody tests to confirm if Hashimoto's disease is the cause.

In autoimmune conditions, antibodies are mistakenly made by your body to attack your own organs. In Hashimoto's disease, the immune system produces an antibody to thyroid peroxidase (TPO) that plays a critical role in thyroid hormone production.

Most people with the condition will have traces of TPO antibodies in their blood. It is also common for doctors to request other lab tests to check for antibodies often associated with the condition.

Complications of Hashimoto's disease

So, how serious is Hashimoto's disease? Hashimoto's disease can be easily overlooked since its symptoms are similar to many other conditions, making it difficult to spot. The severity of the disease usually leads to other complications that can be fatal, such as heart problems or heart failure.

If Hashimoto’s disease goes untreated, the individual could die of disease complications in some rare cases.

Here are some other complications that are possible results of untreated Hashimoto's disease:

  • Over-replacement with thyroxine

  • Hyperlipidemia and consequences

  • Hashimoto's encephalopathy 

  • Myxoedema coma 

  • High blood pressure 

  • High cholesterol

If Hashimoto's disease starts to progress towards thyroid hormone deficiency (hypothyroidism), it can be treated through hormone replacement therapy.

With early diagnosis and levothyroxine replacement therapy, the outlook for those with Hashimoto's disease is excellent, and people may achieve normal thyroid levels. However, note that normal levels do not necessarily mean a return to normal functioning.

How to manage and treat Hashimoto's disease

There is no known cure for Hashimoto's disease, but replacing hormones using synthetic hormone medications has proven to be effective in regulating hormone levels and restoring the body's regular metabolism.

Fortunately, if you have high levels of TPO antibodies but normal thyroid function tests (TSH and Free T4), you do not have to seek treatment. However, your condition should be monitored.

Additionally, those with mild hypothyroidism (slightly elevated TSH) do not necessarily require medication. Instead, they should have regular testing after three to six months.

Treatment for Hashimoto's disease is recommended for individuals with low thyroid hormone levels and elevated TSH, also known as overt hypothyroidism. Usually, treatment revolves around synthetic hormone medications and hormone replacement therapies, such as T4 hormone replacement therapy and occasional T3 hormone replacement therapy.

The lowdown

On its own, Hashimoto's disease does not pose much of a threat. However, if allowed to develop and progress over time, it can lead to severe complications, such as heart failure. It is recommended to visit a physician if you experience any of the symptoms associated with Hashimoto's disease.

Since this condition presents symptoms similar to other conditions, the physician will require blood tests to confirm the diagnosis.

  1. Hashimoto thyroiditis | MedlinePlus

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