Thyroid diseases refer to diseases that affect the thyroid glands and hamper its functions, whether it is hypothyroidism, hyperthyroidism, thyroid cancer, etc. Thyroid diseases are serious diseases although they can be treated because if they are ignored, they can cause many health problems that may eventually lead to death. There are also lots of causes for the occurrence of thyroid diseases and one major cause is diet. In other words, if your diet is unhealthy and not friendly to the thyroid glands, there is a higher risk for you to acquire these diseases.