Alternate Names: Diffuse thyrotoxic goiter

Causes and Risks:

Located in the front of the neck just below the larynx, the thyroid gland is an important organ of the endocrine system. The thyroid gland secretes the hormones thyroxine (T4), triiodothyronine (T3), and calcitonin ,which control body metabolism and regulate calcium balance.

The secretion of T3 and T4 by the thyroid is controlled by an endocrine feedback system involving the pituitary gland and the hypothalamus in the brain. Calcitonin is regulated by the amount of calcium in the blood and acts in conjunction with the parathyroid gland to control calcium levels.

Since the thyroid gland is regulated by the pituitary gland and the hypothalamus, thyroid disorders may result not only from defects in the gland itself, but also from disruption of the control system. Thyroid disorders caused by overproduction of thyroid hormones are called hyperthyroidism, and underproduction of these hormones is known as hypothyroidism.

Graves’ disease is the most common causes of hyperthyroidism. The production of thyroid hormone is increased resulting in many changes within the body. The cause of the disease may be related to a genetic or immune system disorder.

Other disorders of the endocrine system may be present in people with Graves’ disease. The symptoms of hyperthyroidism are present and, in addition, the eyeballs may protrude (exophthalmos) causing irritation and tearing.

Risk factors are being female over 20 years old, although the disorder may occur at any age.

Prevention: There is no known way to prevent Graves' Disease.

Symptoms:

• Protruding eyes (less common in children)
• Weight loss
• Increased appetite
• Nervousness
• Restlessness
• Heat intolerance
• Increased sweating
• Fatigue
• Muscle cramps
• Tremor
• Frequent bowel movements
• Menstrual irregularities in women
• Goiter (possible)

Signs and Tests: Physical examination shows an increased heart rate. Examination of the neck may show thyroid enlargement or goiter.

• Serum TSH is decreased
• Serum T3, T4, T3 resin uptake are usually elevated
• Radioactive iodine uptake is usually increased

• TSI
• Orbit CT scan

Treatment: The purpose of treatment is to control the overactivity of the thyroid gland. Beta-blockers (e.g., propranolol) are often used to treat symptoms of rapid heart rate, sweating, and anxiety until the hyperthyroidism is controlled. Hyperthyroidism is treated with antithyroid medications, radioactive iodine, or surgery to remove a portion of the thyroid gland.

The eye problems of Graves’ disease usually resolve with treatment of the underlying disorder. Sometimes prednisone is required for severe inflammation. Taping the eyes closed at night to prevent drying is sometimes indicated. Sunglasses and eyedrops may lessen irritation of the eyes. Rarely, surgical decompression of the orbit may be required.

Prognosis: For most people, Graves’ disease responds well to treatment, but lifelong observation by a health care professional is important because of possible serious complications associated with the disease. Thyroid surgery or radioactive iodine can result in hypothyroidism. Side effects may be caused by antithyroid medications.

Complications:

• Eye problems associated with the disease (called Graves’ ophthalmopathy or exophthalmos)
• Cardiac complications including rapid heart rate, congestive failure (especially in the elderly), and atrial fibrillation
• Thyroid crisis or "storm," a severe worsening or exaggeration of the symptoms of overactivity of the thyroid gland
• Increased risk for osteoporosis

Call for an appointment with your health care provider if eye problems, or general symptoms worsen (or do not improve) with treatment. You should also call if rapid heart rate, chest pain, difficulty breathing, or other new symptoms appear.