What Is Hashimoto’s Disease?

Hashimoto’s disease is an autoimmune disease affecting the thyroid. The thyroid is a gland in your neck that produces hormones that tell your body how to use energy. Hashimoto’s disease damages the thyroid, causing thyrotoxicosis. Thyrotoxicosis is when preformed thyroid hormone is released into the bloodstream in large quantities. This thyrotoxic phase is usually followed by a hypothyroid phase, where there aren't enough thyroid hormones in the bloodstream.

This disease is also known as Hashimoto’s thyroiditis, chronic lymphocytic thyroiditis, or autoimmune thyroiditis.

It isn’t known exactly how many people have Hashimoto’s disease, but it is the most common cause of underactive thyroid. Hypothyroidism affects about 5% of people in the United States. The disease is estimated to be four to ten times more common in women than in men.

Hashimoto’s Disease Symptoms

The symptoms of Hashimoto’s disease tend to be similar to other thyroid conditions. At the beginning of the disease, you may have no symptoms or mild symptoms which may increase over time. Common symptoms of Hashimoto’s disease are:

  • Increased tiredness
  • Weight gain
  • Constipation
  • Sensitivity to cold
  • Fertility problems
  • Irregular or heavy menstrual periods
  • Pain in muscles and joints not explained by other causes
  • Decreased heart rate
  • Dry skin
  • Thinning hair

In the less likely case that Hashimoto’s disease causes overactive thyroid, symptoms may include:

  • Anxiety and irritability
  • Sweating
  • Hand tremors
  • Increased or “racing” heart rate
  • Difficulty sleeping
  • Weight loss

Some people with Hashimoto’s disease get something called a “goiter.” This is a swelling at the front of the throat caused by the thyroid becoming enlarged. The goiter may create an uncomfortable feeling of fullness in the throat but is not generally reported to be painful. Goiters can go away on their own, but some choose to have it removed surgically.


Hashimoto’s disease occurs when your own immune system attacks your thyroid and it becomes too damaged to fulfill its role of making thyroid hormones. Scientists have not yet found an exact reason why people develop Hashimoto’s disease, but it often runs in families. The current hypothesis is that Hashimoto’s disease is caused when someone who is genetically predisposed is then exposed to a trigger in the environment, but further research is needed.

Researchers are still conducting studies to confirm which environmental factors can cause or protect you from Hashimoto’s disease. The following are some of the factors thought to contribute to triggering Hashimoto’s disease:

  • Hepatitis C infections are thought to trigger autoimmune thyroid disorders like Hashimoto’s disease. The virus has been shown to destroy thyroid tissue.
  • Certain medications or medical therapies affect how the immune system functions, including lithium (a medication known as a mood stabilizer) or irradiation (too much exposure to radiation).
  • Consuming too much iodine, whether in your diet or in medications.
  • There is some evidence to suggest that excess stress may be a cause of Hashimoto’s disease, but more research is needed in this area.

Risk factors for this disease include increased age, being female, being pregnant, having Down’s syndrome, and having other autoimmune disorders.

How Is Hashimoto’s Disease Diagnosed?

The first steps a healthcare provider will take toward diagnosing you are asking about your medical history and performing a physical exam. They will ask about your symptoms and if you have a family history of Hashimoto’s disease. If you are concerned you may have Hashimoto’s disease and know this illness runs in your family be sure to let your provider know. They may also feel your neck for the presence of a goiter.

Your provider will likely order one or more blood tests to confirm a diagnosis. These tests will measure:

  • Triiodothyronine (T4): T4 is a thyroid hormone. Usually, a high blood level of T4 means you have hyperthyroidism and a low level means you have hypothyroidism.
  • Thyroxine (T3): T3 is another thyroid hormone. You may have hyperthyroidism even though your T4 level is normal, so a T3 test is used to confirm the diagnosis. Like T4, a high blood level of T3 indicates hyperthyroidism and a low level indicates hypothyroidism.
  • Thyroid-stimulating hormone (TSH): This is a hormone made in the pituitary gland (the small gland located below your hypothalamus at the base of your brain) that tells the thyroid how much T4 and T3 to make. A high TSH level often indicates hypothyroidism and a low TSH level usually indicates hyperthyroidism.
  • Thyroid antibody tests: Testing for certain proteins made by the immune system (called antibodies) can help diagnose an autoimmune thyroid disorder. Your provider may use this test after doing the other tests listed above to confirm your diagnosis.

In most cases, the blood tests will be enough to confirm a diagnosis. Occasionally, the blood tests may not be enough. These people may get an ultrasound of their thyroid. An ultrasound is a type of imaging that allows your provider to see the size of your thyroid as well as other features that may confirm a Hashimoto’s disease diagnosis.


While there is no cure for Hashimoto’s, there are effective medications and lifestyle modifications that can reduce or eliminate symptoms. The most common treatment for Hashimoto’s disease is the medication levothyroxine, also known under the brand names Levothroid, Levoxyl, Synthroid, Tirosint, Tirosint-Sol, and Unithroid. Levothyroxine comes in pill or capsule form and is identical to the thyroid hormone T4. 

While this isn’t a cure, replacing this hormone with a pill can reduce or eliminate symptoms of hypothyroidism from Hashimoto’s disease. It is commonly recommended that you take this pill 30 to 60 minutes before your first meal in the morning. Taking this pill on an empty stomach can be important since many foods and beverages can impair how well your body absorbs the medication. While you are on this medication your provider will order regular blood tests to make sure the medication is at the appropriate dose.

There is some evidence that following an anti-inflammatory diet may help with managing Hashimoto’s disease. An anti-inflammatory diet encourages plant-based protein and fish, increased fiber, plenty of fruit and vegetables, and certain herbs and spices. While this diet has been proven to help many chronic illnesses, more research is still needed on how effective it is for Hashimoto’s disease.


Since the cause of Hashimoto's disease isn’t known, there is no sure way to prevent it. However, reducing your exposure to environmental factors known to cause Hashimoto’s disease may be a way to lower your risk of developing the illness. 

For example, hepatitis C is transmitted through contact with the bodily fluids (blood, semen, etc.)  of a person with hepatitis C. Using barrier protection during sex and never sharing sharps like needles or razors could reduce the risk of catching it.

Comorbid Conditions

Research has shown that people with Hashimoto’s disease are more likely to have other autoimmune disorders. This is more prevalent in adults than in children and adolescents but was found in both groups. Some autoimmune disorders that occurred with Hashimoto’s disease were more likely to be present in adults rather than children and vice versa.

Comorbid autoimmune disorders more likely to be found in adults include:

  • Arthropathies: Diseases affecting the joints like psoriatic arthritis and rheumatoid arthritis.
  • Connective tissue diseases: Connective tissue includes fat, bone, blood, cartilage, and lymphatic tissue. The most common connective tissue disease in this study was Sjögren’s syndrome, a disease that causes dry eyes and mouth.

The comorbidities more commonly found in children and adolescents include:

  • Celiac disease: This disease damages the small intestine and is provoked by eating foods with gluten in them.
  • Type 1 diabetes: A condition where the pancreas can no longer make enough (or any) insulin, a hormone needed to control blood sugar.

Several autoimmune disorders such as vitiligo, a skin condition, and Addison’s disease, a condition that affects the adrenal glands, occurred at a similar rate between age groups.

Living with Hashimoto’s Disease:

The outlook for living with Hashimoto’s disease is a good one. Many people are able to reduce or get rid of their symptoms by taking the thyroid medication levothyroxine as prescribed and getting regular blood tests. It is important to not stop or change your treatment unless you are told to by your healthcare provider. While there is not currently a cure for Hashimoto’s disease, studies exploring new treatments are being performed regularly.

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17 Sources
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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