http://articles.mercola.com/sites/articles/archive/2000/07/02/smoking-thyroid.aspxMany people assume that the only serious negative effects of smoking are on the lungs. However, this study of 132 pairs of twins (264 subjects) showed that smoking can have negative effects on the endocrine system as well, causing a 3 to 5 fold increaseenCommunityServer 2008.5 SP1 (Build: 31106.3070)