Diffuse thyrotoxic goiter

Definition

Graves disease is an autoimmune disorder that involves overactivity of the thyroid gland (hyperthyroidism).

Alternative Names

Causes

The thyroid gland is an important organ of the endocrine system. It is located in the front of the neck just below the voice box. This gland releases the hormones thyroxine (T4) and triiodothyronine (T3), which control body metabolism. Control of metabolism is critical in controlling mood, weight, and mental and physical energy levels.

If the body makes too much thyroid hormone, the condition is called hyperthyroidism. (An underactive thyroid leads to hypothyroidism

Graves disease is the most common cause of hyperthyroidism. The production of thyroid hormone is increased, causing a wide range of symptoms from anxiety and restlessness to insomnia and weight loss. In addition, the eyeballs may begin to stick out (exophthalmos), causing eye irritation and tearing.

Graves disease is caused by an abnormal immune system response that attacks the thyroid gland, and causes too much production of thyroid hormones. Risk factors are being a woman over 20 years old, although the disorder may occur at any age and may affect men as well.

Symptoms

• Protruding eyes (less common in children)
• Weight loss
• Increased appetite
• Nervousness
• Restlessness
• Heat intolerance
• Increased sweating
• Fatigue
• Muscle weakness
• Double vision
• Eye irritation
• Breast enlargement in men (possible)
• Tremor
• Frequent bowel movements
• Menstrual irregularities in women
• Goiter (possible)

Exams and Tests

Physical examination shows an increased heart rate. Examination of the neck may show thyroid enlargement (goiter).

• Serum TSH is decreased
• Serum T3, free T4 are higher than normal
• Radioactive iodine uptake is usually high

• TSI
• Orbit CT scan or ultrasound

Treatment

The purpose of treatment is to control the overactivity of the thyroid gland. Beta-blockers such as 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.

Both radiation and surgery result in the need for lifelong use of replacement thyroid hormones, because these treatments destroy or remove the gland.

The eye problems related to Graves disease usually disappear when medications, radiation, or surgery solve the hyperthyroidism problem. Sometimes use of prednisone (a steroid medication, which suppresses the immune system) is required to reduce eye irritation and swelling.

Taping the eyes closed at night to prevent drying may sometimes be required. Sunglasses and eyedrops may lessen irritation of the eyes. Rarely, surgery may be needed to return the eyes to their normal position.

Outlook (Prognosis)

For most people, Graves disease responds well to treatment. However, thyroid surgery or radioactive iodine will sometimes cause hypothyroidism, which can lead to weight gain, depression, and mental and physical sluggishness. Antithyroid medications can also have serious side effects.

Possible Complications

• Eye problems associated with the disease (called Graves ophthalmopathy or exophthalmos)
• heart complications including rapid heart rate, congestive heart failure (especially in the elderly) and atrial fibrillation
• Thyroid crisis (thyrotoxic storm), a severe worsening of the symptoms of an overactive thyroid gland
• Increased risk for osteoporosis
• Inadequate levels of thyroid hormone medications following surgery or radiation, leading to fatigue, elevated cholesterol levels, mild weight gain, depression, and mental and physical sluggishness
• Complications related to surgery, including:
  • Visible scarring of the neck
  • Hoarseness due to damage of the nerve leading to the voice box
  • Low calcium levels due to damage to the parathyroid glands

When to Contact a Medical Professional

Call your health care provider if you have symptoms suggestive of Graves disease. Also call if eye problems or general symptoms get worse (or do not improve) with treatment.

Go to the emergency room or call the local emergency number (such as 911) if symptoms of hyperthyroidism are associated with a rapid, irregular heart beat, fever, or a decrease in consciousness.