What causes it? If you have not had your thyroid gland surgically removed or ablated there is only one cause of hypothyroidism, and the fancy medical name for this is Hashimoto’s disease (named after Dr. Hashimoto, who first described the disease). It comes from our body’s immune system – what we use to fight infection. The immune system makes antibodies against specific infections. Those antibodies typically stay with us for a long time. If the infection comes back they