Free thyroxine 59.62 pmol / L is not normal, the normal reference value range is 11.5 ~ 22.7 pmol / L, so the free thyroxine 59.62 pmol / L belongs to the high, may be caused by pregnancy, may also be hyperthyroidism, thyroiditis and other diseases. 1. Pregnancy: If the patient with high free thyroxine is in pregnancy, due to the change of progesterone level in the body, it will lead to the patient’s free thyroxine appearing higher than normal, which is a temporary elevation. 2. Hyperthyroidism: Hyperthyroidism is mainly caused by overactive thyroid function, and the main symptoms of patients are agitation, irritability, tachycardia, fear of heat and weight loss. 3. Other: Hashimoto’s thyroiditis, painless thyroiditis and other diseases can also lead to high free thyroxine. When patients have symptoms of free thyroxine, it may be caused by pregnancy, and usually will recover by itself. If it is caused by a disease, the patient should seek medical attention and follow the doctor’s instructions.