Causes, incidence, and risk factors
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. Controlling metabolism is critical for regulating 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. It is caused by an abnormal immune system response that causes the thyroid gland to produce too much thyroid hormones. Graves disease is most common in women over age 20. However, the disorder may occur at any age and may affect men as well.
Symptoms
Anxiety
Breast enlargement in men (possible)
Difficulty concentrating
Double vision
Eyeballs that stick out (exophthalmos)
Eye irritation and tearing
Fatigue
Frequent bowel movements
Goiter (possible)
Heat intolerance
Increased appetite
Increased sweating
Insomnia
Menstrual irregularities in women
Muscle weakness
Nervousness
Rapid or irregular heartbeat (palpitations or arrhythmia)
Restlessness and difficulty sleeping
Shortness of breath with exertion
Tremor
Weight loss (rarely, weight gain)
Signs and tests
Physical examination shows an increased heart rate. Examination of the neck may show that the thyroid gland is enlarged (goiter).
Other tests include:
Blood tests to measure levels of TSH, T3, and free T4
Radioactive iodine uptake
This disease may also affect the following test results:
Orbit CT scan or ultrasound
Thyroid stimulating immunoglobulin (TSI)
Thyroid peroxidase (TPO) antibody
Anti-TSH receptor antibody
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 one or more of the following:
Antithyroid medications
Radioactive iodine
Surgery
If you have radiation and surgery, you will need to take replacement thyroid hormones for the rest of your life, because these treatments destroy or remove the gland.
Some of the eye problems related to Graves disease usually improve when hyperthyroidism is treated with medications, radiation, or surgery. Radioactive iodine can sometimes make eye problems worse. Eye problems are worse in people who smoke, even after the hyperthyroidism is cured.
Sometimes prednisone (a steroid medication that suppresses the immune system) is needed to reduce eye irritation and swelling.
You may need to tape your eyes closed at night to prevent drying. Sunglasses and eyedrops may reduce eye irritation. Rarely, surgery or radiation therapy (different from radioactive iodine) may be needed to return the eyes to their normal position.
Expectations (prognosis)
Graves disease often responds well to treatment. However, thyroid surgery or radioactive iodine usually will cause hypothyroidism. Without getting the correct dose of thyroid hormone replacement, hypothyroidism can lead to:
Depression
Mental and physical sluggishness
Weight gain
Antithyroid medications can also have serious side effects.
Complications
Complications from surgery, including:
Hoarseness from damage to the nerve leading to the voice box
Low calcium levels from damage to the parathyroid glands (located near the thyroid gland)
Scarring of the neck
Eye problems (called Graves ophthalmopathy or exophthalmos)
Heart-related complications, including:
Rapid heart rate
Congestive heart failure (especially in the elderly)
Atrial fibrillation
Thyroid crisis (thyrotoxic storm), a severe worsening of overactive thyroid gland symptoms
Increased risk for osteoporosis, if hyperthyroidism is present for a long time
Complications related to thyroid hormone replacement
If too little hormone is given, fatigue, weight gain, high cholesterol, depression, physical sluggishness, and other symptoms of hypothyroidism can occur
If too much hormone is given, symptoms of hyperthyroidism will return
Calling your health care provider
Call your health care provider if you have symptoms of Graves disease. Also call if your 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 you have symptoms of hyperthyroidism with:
Decrease in consciousness
Fever
Rapid, irregular heartbeat
Article Source: http://www.ncbi.nlm.nih.gov
