What is Hashimoto's (Hashimoto's thyroiditis)?

From the Guidelines

Hashimoto's thyroiditis is an autoimmune disorder where the immune system attacks the thyroid gland, leading to chronic inflammation and eventual hypothyroidism. This condition is the most common cause of hypothyroidism in the United States, with risk factors including female sex, advancing age, white race, type 1 diabetes, Down syndrome, family history of thyroid disease, goiter, previous hyperthyroidism, and external-beam radiation in the head and neck area 1.

Key Characteristics

• The condition leads to chronic inflammation and damage to the thyroid gland, resulting in hypothyroidism.
• Risk factors include female sex, advancing age, and a family history of thyroid disease.
• The serum TSH test is the primary screening test for thyroid dysfunction, with multiple tests done over a 3- to 6-month interval to confirm or rule out abnormal findings 1.

Treatment and Management

• Treatment typically involves daily synthetic thyroid hormone replacement, most commonly levothyroxine (brand names include Synthroid, Levoxyl), usually starting at 1.6 mcg/kg body weight per day, taken on an empty stomach 30-60 minutes before breakfast 1.
• Regular blood tests to monitor thyroid-stimulating hormone (TSH) levels are necessary, with target levels generally between 0.5-2.5 mIU/L, though this may vary based on individual factors.
• Patients should avoid taking calcium, iron supplements, or certain antacids within 4 hours of levothyroxine as these can interfere with absorption.
• While medication treats the resulting hypothyroidism, it doesn't stop the autoimmune process.
• Some patients benefit from dietary changes like reducing gluten or inflammatory foods, though scientific evidence for these approaches varies 1.

Lifelong Management

• The condition requires lifelong management, as the thyroid gland typically becomes increasingly damaged over time, necessitating continued hormone replacement to maintain normal metabolism and prevent symptoms like fatigue, weight gain, cold intolerance, and depression.
• Regular monitoring and dose adjustments are crucial to ensure optimal treatment outcomes and minimize the risk of complications.

From the FDA Drug Label

As pituitary thyroid-stimulating hormone (TSH) suppressants, in the treatment or prevention of various types of euthyroid goiters, including thyroid nodules, subacute or chronic lymphocytic thyroiditis (Hashimoto's) and multinodular goiter Hashimoto's is another term for chronic lymphocytic thyroiditis, a condition where the thyroid gland is inflamed. 2

From the Research

Definition and Overview of Hashimoto's Thyroiditis

• Hashimoto's thyroiditis (HT) is considered the most common autoimmune disease 3.
• It is characterized by the immune system attacking the thyroid gland, leading to inflammation and damage.
• The development of HT is influenced by genetic susceptibility, environmental factors, and immune disorders.

Symptoms and Clinical Manifestations

• Common presenting symptoms of Hashimoto's thyroiditis may include anxiety, negative mood, depression, dry skin, cold intolerance, puffy eyes, muscle cramps, and fatigue 4.
• Clinical manifestations of the disease are defined primarily by low levels of thyroid hormones.
• HT patients often experience hypothyroidism, which can be treated with hormone replacement therapy, usually consisting of levothyroxine (LT4).

Nutritional Factors and Hashimoto's Thyroiditis

• High iodine intake and deficiencies of selenium and iron have been implicated in the development of HT 3.
• Vitamin D status has also been found to be lower in HT patients, although its role in the disease is still unclear.
• Adequate selenium intake is vital, particularly in areas of iodine deficiency or excess, and supplements may be necessary in regions with low selenium intake.

Treatment and Management

• Levothyroxine (LT4) monotherapy is the standard treatment for primary hypothyroidism, including HT 5.
• Treatment is monitored with serum TSH levels, aiming for a target range of 0.5-2.0 mIU/L.
• Clinicians should check patients' iron and vitamin D status to correct any deficiencies, especially in menstruating women.