Chronic thyroiditis is an inflammation of the thyroid gland that frequently results in hypothyroidism (lowered thyroid function).

Chronic thyroiditis or Hashimoto's disease is a common thyroid gland disorder that can occur at any age, but it is most often seen in middle aged women. It is caused by a reaction of the immune system against the thyroid gland.

The onset of the disease is slow, and it may take months or even years for the condition to be detected. Chronic thyroiditis is most common in women and individuals with a family history of thyroid disease. It is estimated to affect between 0.1% and 5% of all adults in Western countries.

Hashimoto's disease may rarely be associated with other endocrine disorders caused by the immune system. When Hashimoto's disease occurs with adrenal insufficiency and type 1 diabetes, the condition is called type 2 polyglandular autoimmune syndrome (PGA II).

Less commonly, Hashimoto's disease occurs with hypoparathyroidism, adrenal insufficiency, and fungal infections of the mouth and nails in a condition called type 1 polyglandular autoimmune syndrome (PGA I).

• Intolerance to cold
• Weight gain - mild
• Fatigue
• Constipation
• Enlarged neck or presence of goiter
• Small or atrophic thyroid gland (late in the disease)
• Dry skin
• Hair loss
• Heavy and irregular menses
• Difficulty concentrating or thinking

Additional symptoms that may be associated with this disease:

• Weight gain (unintentional)
• Joint stiffness
• Facial swelling

Note: There may be no symptoms.

Laboratory tests to determine thyroid function include:

• Free T4 test (low)
• Serum TSH (high)
• T3 (low or normal)
• Thyroid autoantibodies are frequently present:
  • antithyroid peroxidase antibody
  • antithyroglobulin antibody

This disease may also alter the results of the following tests:

• Radioactive iodine uptake
• Complete blood count
• Total cholesterol
• Serum sodium
• Serum prolactin