Goiter
Goiter is the swelling of the thyroid gland, which is located in the neck just below the Adam’s apple. In severe cases, it can be painful and cause difficulty swallowing and breathing.
Iodine deficiency causes goiter because it prevents the thyroid from making enough of a hormone called thyroxine. This is also known as T4 or levothyroxine sodium (LT4). This hormone helps regulate how fast the body burns energy. Without enough T4, the metabolism slows down, and it may develop symptoms like tiredness, weight gain, and increased sensitivity to colder temperatures. These are all signs of hypothyroidism.
When a person has too little iodine in their body, the thyroid gland doesn’t get the signal to make T4. So instead, it creates another hormone called TSH (thyroid-stimulating hormone), which tells the pituitary gland to release more T4. The pituitary gland then releases more TSH, and so on, until they finally end up with enough T4 in the bloodstream.
