At the front of our neck is a tiny organ, the thyroid gland (thyroid). It is like a butterfly with its wings spread out close to the front of the trachea. It is not visible in normal people, but can be seen in outline during special physiological periods such as puberty or pregnancy, or in cases of thyroid disease, when it appears enlarged. The thyroid gland is the largest endocrine organ in the body, although it is not conspicuous among the organs, and its function is related to the growth and development of the body and its metabolism. It helps the body to produce heat like a furnace, and it is like the internal combustion engine of life. Without it, people have no enthusiasm, life lacks power, and the quality of life decreases. In recent years, the incidence of thyroid disease has been rising year by year. According to the findings of the First Epidemiology of Thyroid Diseases in Ten Cities in China, the incidence of hyperthyroidism (hyperthyroidism) and hypothyroidism (hypothyroidism) can be as high as 3.7% and 6.5%, respectively, with a preference for women. Because most thyroid disorders are insidious, nearly 50% of patients are unaware that they have these disorders, and thyroid disorders can cause discomfort in a variety of organs and tissues and are often mistaken for heart disease, kidney disease, neurological or psychiatric disorders, leading to misdiagnosis and mismanagement. Hyperthyroidism is a condition caused by the synthesis and release of too much thyroid hormone by the thyroid gland. The most common cause of hyperthyroidism is an autoimmune disease called “Graves’ disease”, which accounts for 85% of all hyperthyroidism. A few cases of transient hyperthyroidism can be caused by inflammatory conditions (e.g. subacute thyroiditis, painless thyroiditis and postpartum thyroiditis), which mostly resolve themselves without the use of medication. Patients may have symptoms such as panic attacks, fear of heat, excessive sweating, hyperphagia, weight loss, agitation, drowsiness, insomnia, protruding eyes and increased stool frequency. Hyperthyroidism is curable. Patients with hyperthyroidism should take rest, avoid infections and emotional stress, and avoid seafood such as sea fish, seaweed and nori, spicy and stimulating foods, coffee, tobacco and alcohol. In Graves’ disease, active treatment and prevention of complications are key. There are three main treatment options: ① antithyroid drug therapy (such as methimazole and propylthiouracil, the former is preferred in the general population), which is suitable for mild to moderate patients, the course of treatment mostly lasts 1-1.5 years, the relapse rate is high, side effects such as skin allergy, bone marrow suppression or liver damage may occur, and regular monitoring of blood and liver function is required during treatment. In recent years, the number of people treated with 131 iodine for hyperthyroidism has increased significantly due to its high cure rate, rapid effect, low recurrence rate, safety and simplicity. As the name implies, hypothyroidism is a disease state caused by insufficient production of thyroid hormones, the most common cause of which is autoimmune thyroiditis, also known as Hashimoto’s disease. In mild cases, there may be no obvious discomfort, but if you have symptoms such as swelling, weight gain, drowsiness, coldness, hair loss, loss of appetite, bloating, constipation, etc., you should be alert to the occurrence of clinical hypothyroidism. Severe hypothyroidism may result in slowed heart rate and shortness of breath, heart failure, arrhythmias or elevated blood lipids, or even serious complications such as pleural fluid, ascites, or pericardial effusion. Women of childbearing age may also experience menstrual disorders, infertility, miscarriage, premature birth and abnormal fetal development. Usually, permanent hypothyroidism is not curable, but it does not mean that it is a terrible “terminal” disease. Happily, hypothyroidism patients can regain their normal health without affecting their life expectancy and have smart, healthy babies by stabilizing their hormone levels with long-term, moderate thyroid hormone supplementation. Therefore, although hyperthyroidism and hypothyroidism are common, they are not terrible. As long as we choose good habits and the right treatment, we can eventually work and live like normal people, and let the “elegant” little butterfly of the thyroid gland continue to be healthy and happy. Let the “elegant” butterfly continue to fly healthy and happy.