Hashimoto Thyroiditis - A Comprehensive Review

Abstract

Hashimoto thyroiditis (HT) is an inflammatory disorder that often results in hypothyroidism. It has several global implications affecting different regions worldwide. Risk factors for acquiring HT include diet, inheritance, sex, epigenetics, and comorbidities. HT is a complex autoimmune illness characterized by an attack on the thyroid gland by the immune system. At the cellular level, genetic predisposition, environmental triggers, and the loss of immunological tolerance to thyroid antigens all play significant roles in the disease's genesis and progression. There are several mechanisms by which HT may develop, but the typical progression is autoimmune in origin. Many patients do not initially present with symptoms, but later develop symptoms of hypothyroidism. These symptoms include constipation, fatigue, dry skin, weight gain, cold intolerance, decreased energy, memory loss, muscle cramps, hair loss, and irregular menses. Patients with HT usually present with a firm, nontender neck goiter on a physical exam. To distinguish HT from other thyroid pathologies, patient serum should be collected to check for thyroid-specific auto-antibodies against thyroglobulin, thyroid peroxidase, thyroid stimulating hormone. Imaging studies such as ultrasonography with computer-aided techniques using gray-scale features are also diagnostic tools in differentiating between a healthy thyroid and HT. While the most common intervention of HT is synthetic hormone administration with levothyroxine sodium (L-T4), other alternatives or additional treatments include glucocorticoid use, diet alterations, selenium supplementation, vitamin D supplementation, and in more extreme cases, thyroidectomy. While research continues discovering new interventions, each treatment plan is highly variable based on underlying causes and presentations. This comprehensive review hopes to provide an up-to-date compact analysis of literature pertinent to the epidemiology, etiology, risk factors, genetics, pathophysiology, classifications, clinical presentation, diagnosis, and treatments of HT.