The severity of hyperthyroidism is related to the degree of elevation of the thyroid function indicators T3 and T4, and there is a direct correlation with the hyperthyroid symptoms of the patient with hyperthyroidism itself. If the elevation of T3 and T4 is more than double, the patient may have a TSH of less than 0.005 mU/L. If T4 is more than 100 nmol/L and T3 is significantly elevated, this is a very serious form of hyperthyroidism and requires immediate treatment with anti-thyroid medication. Thyroid function and blood tests are required before treatment, and changes in blood white blood cells and liver function need to be monitored during treatment.