Goitre related to hypermetabolism, (increased metabolism), excessive thyroid hormone, an increase in oxygen consumption, metabolic changes in protein metabolism, immunologic stimulation of diffuse goitre, and ocular changes (exophthalmos). Hypothyroid individuals may have weight gain despite poor appetite, cold intolerance, constipation and lethargy. However, these symptoms are often non-specific and make diagnosis difficult. A goitre may be classified either as nodular or diffuse. Nodular goitres are either of one nodule (uninodular) or of multiple nodules (multinodular). Worldwide, the most common cause for goitre is iodine deficiency, usually seen in countries that do not use iodized salt. Selenium deficiency is also considered a
Fluorine deficiency Fluorine deficiency Fluoride or fluorine deficiency is a disorder which may cause increased dental caries (or tooth decay, is the breakdown of dental tissues by the acidic products released by the "bacterial fermentation of dietary carbohydrates.") and possibly osteoporosis (a bone disorder which leads to a decrease in bone mass, and an increase in bone fragility), due to a lack of fluoride in the diet. In terms of dietary sources, fish and tea are considered natural sources of fluoride, as well as tap water that has been fluoridated. The extent to which the condition truly exists, and its relationship to