Thyroid gland is a butterfly shaped gland located in front of the neck, which is visible while swallowing. The thyroid gland produces a hormone called thyroxine, under the influence of another hormone called TSH, which is produced by the pituitary gland in the brain. Thyroxine (T4) and Tri-iodothyronine (T3) which is formed from thyroxine, are responsible for the body’s normal metabolic function, growth and development of children and development of the brain in children less than 3 years of age.

Goiter

Enlargement of the thyroid gland is called a goiter. Goiter may be present in case of

• Under-active thyroid gland
• Overactive thyroid gland and
• Deficiency of iodine in the diet

The term endemic goiter refers to goiter that is prevalent in a certain part or region of the world, usually mountain areas where the soil is low in iodine content eg sub-himalayan region in India. Due to availability of iodized salt in India this problem is seen less often these days. Less commonly, substances in the food or water that increase the likelihood of iodine deficiency cause goiter. This can be prevented by dietary supplementation with iodine.