Colloid nodular goiter Health Article

Definition

Colloid nodular goiter is the enlargement of an otherwise normal thyroid gland.

See also: Goiter

Alternative Names

Endemic goiter

Causes, incidence, and risk factors

Colloid nodular goiters are also known as endemic goiters. They are usually caused by not getting enough iodine in the diet.

Colloid nodular goiters tend to occur in certain areas with iodine-poor soil. These areas are usually away from the sea coast. An area is defined as endemic for goiter if more than 10% of children ages 6 - 12 have goiters.

Certain things in the environment may also cause thyroid enlargement.

Small- to moderate-sized goiters are relatively common in the United States. The Great Lakes, Midwest, and Intermountain regions were once known as the "goiter belt." The routine use of iodized table salt now helps prevent this deficiency.

Risk factors for colloid nodular goiters include:

• Being over age 40
• Being female
• Having a family history of goiter
• Living in an area where there is endemic iodine deficiency
• Not getting enough iodine in your diet

Symptoms

• Breathing difficulties (rare)
• Dizziness when the arms are raised above the head (large goiter)
• Enlarged neck veins
• Swallowing difficulties (rare)
• Thyroid swelling (nodule)

Signs and tests

• Blood tests to monitor thyroid function, including thyroid stimulating hormone (high if underactive, low if overactive)
• Radioactive iodine uptake (normal or increased)
• Thyroid scan
• Thyroid ultrasound
• Urinary excretion of iodine (low)

Treatment

Thyroid hormone replacement therapy is prescribed for iodine deficiency. If you can increase the iodine content of your diet, you may no longer need thyroid hormone replacement therapy.

You may need surgery to remove all or part of the thyroid gland if you have a large goiter that doesn't go away with treatment or that restricts swallowing and breathing.

If the goiter is producing too much thyroid hormone, treatment may be needed with:

• Antithyroid medication
• Radioactive iodine
• Surgery