Hypothyroidism: Symptoms, Causes, and Diagnosis

Hypothyroidism is underactive thyroid hormone production. This article covers common symptoms and why they are not a diagnosis alone, causes including Hashimoto's versus iodine deficiency by setting, TSH and free T4 testing at a high level, why guidelines disagree on treating subclinical hypothyroidism, pregnancy and emergency red flags, and levothyroxine replacement without dosing tables.