Thyroid goitre is a condition that results from a lack of iodine, giving a characteristic swelling in the neck. It used to be found in the days before mass transport in some inland areas including the Midlands and Derbyshire where there is little iodine in the soil and where marine fish was not a part of the regular diet, and consequently became known as "Derbyshire neck". Iodine is normally part of the thyroxine hormone, which is produced by the thyroid gland, found in the oesophagus. Iodine is absorbed from the blood and added to thyroxine as a finishing touch before release of the hormone. If the iodine is not added, the thyroxine accumulates in the gland, causing swelling.