Hashimoto’s thyroiditis, which can be either hypothyroid or hyperthyroid, may have different alterations in thyroid function during the progression of different conditions, and consultation with a physician is recommended. Hashimoto’s thyroiditis has a tendency to progress gradually from hyperthyroidism to normal thyroid function and eventually to hypothyroidism, but this progression is not certain in each individual and its timing is not fixed. Typically, in the early stages of the condition it will manifest as short-term hyperthyroidism, at which time observation or symptomatic treatment is the mainstay, such as controlling the heart rate when it increases. Eventually, when the condition develops into hypothyroidism, it is necessary to choose the appropriate dose of levothyroxine tablets for treatment according to the specific thyroid function. Patients with a confirmed diagnosis of Hashimoto’s thyroiditis are recommended to be treated aggressively under medical supervision.