The term “goiter” refers to an oversized thyroid gland. It is important to note that this does not mean the thyroid gland is not working properly. Goiter may also indicate that there is another cause for which the gland was enlarged.


The reasons for which the thyroid gland can be enlarged are different. The most common of them is the iodine deficiency. Although this was a very common cause for goiter in the past, in the last years it has decreased in recurrence. The main function of the thyroid gland is to concentrate iodine from the blood to produce thyroid hormones. It can not produce enough hormones if there is not enough iodine in the body. Thus, in case of iodine deficiency hypothyroidism is reached. Consequently, the pituitary senses that thyroid hormone levels are low and sends signals for the gland to intesify its activity. This signal is carried out by TSH hormone that stimulates production of hormones. The abnormal increase in size is called goiter. Thus, iodine deficiency leads to the appearance of goiter. Wherever there is a generalized iodine deficiency, goiter will be as common.

Hashimoto thyroiditis is a common cause for the occurrence of goiter. This is an autoimmune disease where the immune system practically destroys the thyroid gland. As the gland is affected, it will be even less able to produce hormones in an optimum amount. As in the previous case, the pituitary senses deficiency of thyroid hormones and secrete more TSH to stimulate thyroid gland activity.

Another reason for goiter is Graves disease. In this case, the immune system produces a protein called thyroid stimulating immunoglobulin, which is responsible for the enlargement of the thyroid gland. Also, thyroid-stimulating immunoglobulin can cause hyperthyroidism.

People who have multinodular goiter have one or more thyroid nodules which tend to widen. This is often detected as a lump sensation in the gland during a physical exam performed by a physician. Patients may have a higher single nodule or a few smaller nodules in the gland which may be felt from the first touch. Unlike the type of goiter presented so far, the exact cause of this type is still not known. Unlike common causes of goiter, in this case there are too few elements in common. Some of these defects can be genetic, others are related to an illness or an infection of the thyroid gland, and others occur due to tumors (malignant or benign).


As mentioned before, the diagnosis of goiter is usually done after a physical examination performed by your doctor. However, the presence of goiter indicates abnormal thyroid function. It is therefore mandatory to determine the exact cause. First, we need to establish weather the thyroid functions under or over the normal values. The subsequent tests depend on the initial results. Other tests that can identify the cause are radioactive iodine scan, thyroid ultrasound and others.

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