Thyroid appearance of cells is viewed to determine whether they resemble normal or cancerous cells. There can be many nodules, which is termed a multinodular goitre, and this can sometimes be a toxic multinodular goitre. An enlarged thyroid gland is called a goitre. Goitres are present in some form in about 5% of people, and are the result of a large number of causes, including iodine deficiency, autoimmune disease (both Grave's disease and Hashimoto's thyroiditis), infection, inflammation, and infltrative disease such as sarcoidosis and amyloidosis. Sometimes no cause can be found, a state called "simple goitre". Some forms of goitre are
Zinc deficiency deficiency is rare, and is mainly seen in persons with acrodermatitis enteropathica, a severe defect in zinc absorption due to a congenital deficiency in the zinc carrier protein ZIP4 in the enterocyte. Mild zinc deficiency due to reduced dietary intake is common. Conservative estimates suggest that 25% of the world's population is at risk of zinc deficiency. Zinc deficiency is thought to be a leading cause of infant mortality. Providing micronutrients, including zinc, to humans is one of the four solutions to major global problems identified in the Copenhagen Consensus from an international panel of economists. Significant historical events related