Definition

The thyroid gland is shaped like a butterfly and located in the front of the neck. It makes hormones that control metabolism. Hashimoto thyroiditis (HT) is caused by a problem with the immune system.

Causes

The body makes antibodies to fight germs. In HT, the body makes antibodies that attack the thyroid. This leads to inflammation and damage of the thyroid. It is not clear why the body begins to make this type of antibody.

Risk Factors

HT is more common in women than in men. It often appears between the ages of 30 and 50.

Factors that may increase the risk of HT include:

• Having other immune system problems, such as Addison disease, rheumatoid arthritis, and celiac disease
• Having family members with HT
• Genetic problems, such as Turner syndrome, Down syndrome, Klinefelter syndrome, and Noonan syndrome
• Occupational exposure to ionizing radiation
• Recent childbirth
• High iodine intake
• Selenium deficiency

Symptoms

Symptoms may not be present during early stages of HT. When symptoms are present, they begin with enlargement of the thyroid gland. The front of the neck may look swollen. This enlargement of the gland is called a goiter.

Other symptoms may include:

• Underactive thyroid (hypothyroidism) symptoms:
  • Fatigue
  • Constipation
  • Weight gain
  • Difficulty tolerating cold temperatures
  • Facial puffiness
  • Dry skin
  • Hair loss
  • A hoarse throat
• Overactive thyroid (hyperthyroidism) symptoms:
  • Rapid heart beat
  • Weight loss
  • Diarrhea
  • Tremors
  • Difficulty sleeping

Diagnosis

You will be asked about your symptoms and medical history. A physical exam will be done. Your body’s fluids will be tested. This can be done with:

• Blood tests to check for anti-thyroid antibodies and thyroid function
• Biopsy and testing of thyroid nodules that concern your doctor

Imaging tests may be done if you have a nodule or goiter. These may include:

• Ultrasound
• PET scan
• Radionuclide imaging

Treatment

Not everybody with HT will need treatment. Regular blood tests and symptom checks will be done to look for any changes. When treatment is needed, options include:

Prevention

There is no known way to prevent HT. It is caused by a problem with the immune system.