When the thyroid produces less thyroid hormone, its metabolism slows down. This is known as hypothyroidism, myxoedema or useless thyroid. It is also known as Hashimoto's disease. The main causes of ineffective thyroid are: Hashimoto's Disease - Antibodies are an autoimmune disease that first triggers the thyroid and then destroys it. Pituitary or hypothalamic failure can cause secondary hypothyroidism Genetic Dysfunction - Congenital thyroid dysfunction or programmed to fail for some time in adult life a behaviour. Environmental challenges or disorders - chemicals and certain foods and beverages can cause thyroid problems Previous thyroid surgery or radioactive iodine therapy Treatment for hyperthyroidism In his opinion, thyroid deficiency is 20% to 50% of a standard population (20 - 50 out of every 100). Click for more info: https://bit.ly/3d58AI6