What Is Hashimoto’s Disease (Chronic Thyroiditis)?

Hashimoto’s disease, also known as chronic lymphocytic thyroiditis or Hashimoto's thyroiditis, is an autoimmune disorder of the thyroid, in which the body’s immune system mistakenly attacks the thyroid as though it were an invasive pathogen. Your thyroid is a small, bowtie-shaped gland at the front of the throat. It is responsible for the secretion of hormones that play key roles in regulating metabolism, or the biochemical processes of energy production and waste elimination.

Given sufficient time, Hashimoto’s disease can develop into a condition called hypothyroidism, in which the thyroid underproduces hormones. The underproduction of thyroid hormones is associated with a slowing down of critical-to-life biological processes, leading to fatigue, weight gain, anxiety, and depression. Fortunately, diagnosis and treatment of hypothyroidism is relatively simple, relying on blood tests and the replacement of underproduced hormones with a synthetic alternative. 

Hashimoto’s disease is the number-one cause of hypothyroidism in the U.S. The latter is surprisingly common, affecting roughly five percent of the population. Women are far more likely to develop this condition than men. In fact, one in five women over the age of 60 will suffer from it. To learn more about Hashimoto’s disease and hypothyroidism, turn to the women’s health team at Baptist Health.

Symptoms

It is possible to have Hashimoto's thyroiditis for years without being aware of it. As the disease progresses, you will eventually show indications of hypothyroidism. The following Hashimoto's disease symptoms are typical:

• Thyroid enlargement, called a goiter
• Muscle fatigue and feelings of weakness
• Slowed heart rate
• Weight gain
• Cold sensitivity
• Facial puffiness
• Achy, swollen joints
• Dry skin and thinning hair
• Constipation
• Increased blood cholesterol
• Memory lapses
• Anxiety and depression

A common early sign of Hashimoto’s disease is the development of an enlarged thyroid or goiter. This is the result of the immune system’s attack on the thyroid, which leads to inflammation and swelling.

Causes

Hashimoto’s disease is an autoimmune condition. Autoimmune diseases occur when the body’s own immune system targets certain tissues for attack. In the case of Hashimoto’s disease, immune-response antibodies attack the thyroid, eventually hampering its ability to produce hormones. The reason for the strong immune response is currently unknown by doctors and healthcare professionals.

Risk Factors

Hashimoto’s disease is strongly associated with certain risk factors:

• Family history: Hashimoto’s disease appears to have a genetic basis, because it tends to run in families. You are more likely to develop this condition if a close relation has this or another autoimmune disorder.
• Sex: There are men with Hashimoto’s disease but it is far more prevalent in women.
• Age: Hashimoto’s disease is most common in middle-aged or older individuals, though it can present at any age.
• Exposure to radiation: Hashimoto’s disease appears correlated to a certain degree of radiation exposure.
• Other autoimmune disorders: The likelihood of developing Hashimoto’s disease increases with other autoimmune conditions, including lupus, rheumatoid arthritis, and type-1 diabetes.

Diagnosis

Hashimoto’s disease is usually diagnosed by diagnosing hypothyroidism. Doing so is typically a two-step process:

• Physical examination: Your physician will ask about your symptoms and record your medical history. He or she will also examine you for evident signs of hypothyroidism, including dulled reflexes, slower heart rate, dry skin, swollen joints, and puffy facial features. 
• Blood tests: A diagnosis of hypothyroidism is confirmed with blood tests. A sample of your blood will be sent to a medical lab for analysis. The lab will be looking for elevated levels of a pituitary hormone called TSH and depressed levels of thyroxine or T4. TSH stimulates the thyroid to produce T4 and other hormones. If TSH levels are high while T4 levels are low, it means that your thyroid is underproducing hormones.

In the case of Hashimoto’s disease, your doctor can also use a blood test to check for the existence of thyroid peroxidase, or TPO, antibodies. TPO is a thyroid enzyme that plays a critical role in the production of hormones. If your body is producing antibodies to attack this enzyme, it may indicate an autoimmune disorder focused on the thyroid.

Treatment

Hashimoto’s disease is often left untreated unless there is evidence for hypothyroidism. There is no cure for the latter but it can be managed with medication. A synthetic (human-made) version of T4 has been shown effective in mimicking the actions of the naturally produced hormone. Once healthy hormone levels are restored, you should see an abatement in your symptoms. This process can take some time, several weeks or more.

Taking too much or too little of synthetic hormone can create unwanted side effects.