Alternate Names: Simple goiter; Euthyroid goiter; Nontoxic nodular goiter; Nontoxic goiter; Nontoxic diffuse goiter

Causes and Risks: A simple goiter occurs when the thyroid gland is unable to meet the metabolic demands of the body through sufficient hormone production. The thyroid gland compensates by enlarging, which usually overcomes mild deficiencies of thyroid hormone.

A simple goiter may be classified as either an endemic goiter (present continuously in a community) or a sporadic goiter. Endemic (also known as colloid) goiters are usually caused by inadequate dietary intake of iodine in geographical areas with iodine-depleted soil, usually areas away from the sea coast. The Great Lakes, Midwest, and Inter-mountain regions of the U.S. are known as the "goiter belt." The use of iodized table salt prevents this deficiency. Iodine deficiency is now rare in the U.S. because of widespread distribution of foods from iodine-sufficient areas and the use of iodized table salt.

Sporadic goiters are caused by swallowing large amounts of certain foods or drugs and does not affect any particular segment of the population. Goitrogenic foods contain substances that decrease thyroid hormone production. Examples of these foods are rutabagas, cabbage, turnips, brussels sprouts, cauliflower, soybeansand radishes. Drugs include lithium, cobalt, iodides, phenylbutazone, and others.

Hereditary factors may cause goiters. Excessive iodine intake is also a cause of goiter. Risk factors are being female, over 40 years old, inadequate dietary intake of iodine, residence in an endemic area, ingestion of large amounts of goitrogenic foods or drugs, and a family history of goiters.

Prevention: The use of iodized table salt prevents endemic goiter. Limiting goitrogenic foods and drugs prevents sporadic goiter.

Symptoms:

• thyroid enlargement varying from a single small nodule to massive enlargement, neck lump
• breathing difficulties or wheezing from compression of the trachea (rare)
• swallowing difficulties from compression of the esophagus
• neck vein distention and dizziness when the arms are raised above the head

Signs and Tests:

• thyroid scan
• ultrasound of thyroid
• high or normal thyroid stimulating hormone
• low or normal T4
• normal or increased radioactive iodine uptake
• low urinary excretion of iodine
• antithyroid microsomal antibody

Treatment: Hormone replacement inhibits thyroid stimulating hormone and allows for recovery of the thyroid gland. Small doses of iodine (Lugol’s or potassium iodine solution) will treat iodine deficiency. Eliminating or reducing goiter producing foods or drugs is indicated for sporadic goiter. A large goiter that is unresponsive to medical management, or restricts swallowing and breathing, may require partial removal of the gland (subtotal thyroidectomy).

Prognosis: The outcome is expected to be good with treatment. Simple goiters may disappear spontaneously, or may become large. Occasionally a person may develop hyperthyroidism with a nodular goiter after receiving excess iodine therapy. More frequently, hypothyroidism develops.

Complications:

• A progressive thyroid enlargement and/or the development of hardened nodules may indicate thyroid malignancy.
• A simple goiter may progress to a toxic nodular goiter.
• Thyrotoxicosis may be a side effect of treatment.

Call your health care provider if you experience any swelling or enlargement in the front of your neck, increased resting pulse rate, palpitations, diarrhea, nausea, vomiting, sweating without exercise of increased room temperature, tremors, agitation, shortness of breath, or signs of hypothyroidism.