The shortage of iodine in the diet is the world’s number one cause of an enlarged thyroid (commonly referred to as “goiter”, Lat. goiter). 1 This is referred to as “iodine-deficiency goiter”, which can occur independent of thyroid dysfunction. In fact, an estimated one billion people worldwide are affected by an iodine deficiency, as the United Nations World Food Program has determined. 2

Goiter formation is not a disorder, which has only emerged in modern times. In China, even approx. 5,000 years ago, foods (such as sea grass), which contain iodine were applied to the treatment of goiter. 3 A goiter forms when the thyroid attempts to compensate the iodine deficiency and the associated low and/or failed hormone production. In this process, it gradually grows from its normal size (the same as the upper part of the thumb).

The larger the thyroid, the greater the risk that also the surrounding organs will be affected. If the thyroid is immensely enlarged, then (for instance), the windpipe, cervical (neck) blood vessels and/or the oesophagus can be displaced or constricted.

In addition to a physical examination, the American Association of Clinical Endocrinologists (AACE) recommends the so-called Neck Check 5 to be able to recognise a possibly-enlarged thyroid.


If a goiter is thought to be present, a medical examination is always essential. Simple visual classification can be inaccurate — primarily due to the possible human error and one’s individual anatomy (e.g. a particularly muscular neck which more readily conceals the enlarged thyroid) — and by no means serve as a substitute for a specific diagnosis by a physician.

Did you know?

Iodine can commonly be found in sea fish, seafood, bread, cheese, cow’s milk, eggs, yoghurt and seaweed.2


  • 1American Thyroid Association. Goiter. 2005 URL (Accessed October 2010)
  • 2United Nations System Standing Committee on Nutrition (SCN) 5th Report on the World Nutrition Situation, Nutrition for improved Development Outcomes – March 2004. URL (Accessed October 2010)
  • 3Lobban C.S., Harrison P.J.: Seaweed Ecology and Physiology. Cambridge University Press (1996)
  • 4Peterson S. et al. Classification of thyroid size by palpation and ultrasonography in field surveys. Lancet 2000,355:106–110.
  • 5American Association of Clinical Endocrinologists (AACE). Neck Check Card. (Accessed November 2010)