Toxic nodular goiter involves an enlarged thyroid gland that contains rounded growths called nodules. These nodules produce too much thyroid hormone.

Toxic multinodular goiter; Plummer's disease

Toxic nodular goiter grows from an existing simple goiter. It occurs most often in the elderly. Risk factors include being female and over 60 years old. This disorder is almost never seen in children.

Sometimes patients with toxic multinodular goiter will develop high thyroid levels for the first time after they receive a large amount of iodine through a vein (intravenously). The iodine may be used as contrast for a CT scan or heart catheterization.

Symptoms are those of  an overactive thyroid gland (hyperthyroidism). However, the bulging eyeballs seen in Graves disease do not occur.

Symptoms include:

• Fatigue
• Frequent bowel movements
• Heat intolerance
• Increased appetite
• Increased sweating
• Irregular menstrual period (in women)
• Muscle cramps
• Nervousness
• Restlessness
• Weight loss

A physical examination will show one or many nodules in the thyroid. There may be a rapid heart rate.

Other tests that may be done:

• Serum thyroid hormone levels (T3, T4)
• Serum TSH (thyroid stimulating hormone)
• Thyroid scan

Treatments include:

• Antithyroid drugs (propylthiouracil, methimazole)
• Radioactive iodine
• Surgery

Beta-blockers (propranolol) can control some of the symptoms of hyperthyroidism until thyroid hormone levels in the body are under control.

Because toxic nodular goiter is mainly a disease of the elderly, other chronic health problems may influence the outcome of this condition. An elderly person may be less able to tolerate the effect of hyperthyroidism on the heart.

Heart complications:

• Congestive heart failure
• Irregular heartbeat (atrial fibrillation)
• Rapid heart rate

Other complications:

• Bone loss leading to osteoporosis

Thyroid crisis or storm is an acute worsening of hyperthyroidism symptoms. It may occur with infection or stress. Thyroid crisis may cause:

• Abdominal pain
• Decreased mental alertness
• Fever

People with this condition need to go to the hospital right away.

Complications of having a very large goiter may include difficulty breathing. This is due to pressure on the airway passage that lies behind the thyroid.

Call your health care provider if you have symptoms of this disorder. Follow the health care provider's recommendations for follow-up visits.

To prevent toxic nodular goiter, treat hyperthyroidism and simple goiter as your health care provider recommends.

Ladenson P, Kim M. Thyroid. In: Goldman L and Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders; 2007:chap 244.

Davies TF, Larsen PR. Thyrotoxicosis. In: Kronenberg HM, Melmed S, Polonsky KS, Larsen PR, eds. Williams Textbook of Endocrinology. 11th ed. Philadelphia, Pa: Saunders Elsevier;2008:chap 11.