Graves disease is an autoimmune disorder that leads to an overactive thyroid gland (hyperthyroidism). An autoimmune disorder is a condition that occurs when the immune system mistakenly attacks healthy tissue.
The thyroid gland is an important organ of the endocrine system. The gland is located at the front of the neck above where the collarbones meet. This gland releases the hormones thyroxine (T4) and triiodothyronine (T3), which control body metabolism. Controlling metabolism is important for regulating mood, weight, and mental and physical energy levels.
Endocrine glands release (secrete) hormones into the bloodstream. The endocrine glands include:AdrenalHypothalamusIslets of Langerhans in the pancrea...Read Article Now Book Mark Article
T4 (thyroxine) is the main hormone produced by the thyroid gland. A laboratory test can be done to measure the amount of free T4 in your blood. Fre...Read Article Now Book Mark Article
Triiodothyronine (T3) is a thyroid hormone. It plays an important role in the body's control of metabolism (the many processes that control the rate...Read Article Now Book Mark Article
Metabolism refers to all the physical and chemical processes in the body that convert or use energy, such as:BreathingCirculating bloodControlling bo...Read Article Now Book Mark Article
Hyperthyroidism is a condition in which the thyroid gland makes too much thyroid hormone. The condition is often called overactive thyroid.Read Article Now Book Mark Article
Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone. This condition is often called underactive thyroid....Read Article Now Book Mark Article
Hyperthyroidism - Animation
You're restless and nervous. You feel hungry all the time, but no matter how much you eat, you keep losing weight. You can't sleep or concentrate, and you feel hot and sweaty. If symptoms like these are putting you on edge, the problem may be an overactive thyroid gland, or hyperthyroidism. This little butterfly-shaped structure in your neck is your thyroid gland. It's job is to release the hormones that help control your body's energy levels, a process known as metabolism. When you have hyperthyroidism, that little gland goes into overdrive, releasing too much of its hormones. Having too much thyroid hormone is like putting your body in fast forward, everything speeds up. That's why you feel shaky, hungry, and your heart feels like it's pounding. So, what causes hyperthyroidism? You can develop an overactive thyroid because you've gotten too much iodine, an element the thyroid uses to make its hormones. Or, you might have a growth on your thyroid that's causing the excess hormone production. But many people with hyperthyroidism have an autoimmune disorder called Graves disease, which also makes their eyes bulge out. During an exam, your doctor may notice that your thyroid is larger than normal, and that you have high blood pressure, tremors, or a fast heart rate. These can all be signs of hypothyroidism. You'll probably have a blood test to check the levels of your thyroid hormones. If you do have an overactive thyroid, you may need to take medicine to slow down the gland and its hormone production. Or, your doctor may suggest having surgery to remove some or all of the thyroid, or taking radioactive iodine to destroy it. If you have surgery or radioactive iodine treatment, you'll probably need to take thyroid hormones for the rest of your life to replace the ones your body can no longer make. You can't prevent hyperthyroidism, but once you have it, it's usually pretty easy to treat. With the right treatment you can finally be free from its symptoms. While you're being treated, watch out for an emergency condition called thyroid crisis, or thyroid storm, which can set in if you've been under a lot of stress or have an infection. If you have a fever, fast and unsteady heartbeat, or you feel less alert than usual, call your emergency services number or go to the ER right away.
Graves disease is the most common cause of hyperthyroidism. It is due to an abnormal immune system response that causes the thyroid gland to produce too much thyroid hormone. Graves disease is most common in women over age 20. But the disorder can occur at any age and can affect men as well.
Younger people may have these symptoms:
- Anxiety or nervousness, as well as problems sleeping
- Breast enlargement in men (possible)
- Problems concentrating
- Frequent bowel movements
- Hair loss
- Heat intolerance and increased sweating
- Increased appetite, despite having weight loss
- Irregular menstrual periods in women
- Muscle weakness of the hips and shoulders
- Moodiness, including irritability and anger
- Palpitations (sensation of a strong or unusual heartbeat)
- Rapid or irregular heartbeat
- Shortness of breath with activity
- Tremor (shakiness of the hands)
Many people with Graves disease have problems with their eyes:
- The eyeballs may seem to be bulging out and may be painful.
- Eyes can feel irritated, itchy or be tearing more frequently.
- Double vision may be present.
- Decreased vision and damage to the cornea can also occur in severe cases.
Older people may have these symptoms:
Exams and Tests
The health care provider will do a physical exam and may find that you have an increased heart rate. An exam of your neck may find that your thyroid gland is enlarged (goiter).
Other tests include:
- Blood tests to measure levels of TSH, T3, and free T4
- Radioactive iodine uptake and scan
This disease may also affect the following test results:
Treatment is aimed at controlling your overactive thyroid. Medicines called beta-blockers 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 medicines can block or change how the thyroid gland uses iodine. These may be used to control the overactive thyroid gland before surgery or radioiodine therapy or as a long-term treatment.
- Radioiodine therapy in which radioactive iodine is given by mouth. It then concentrates in the overactive thyroid tissue and causes damage.
- Surgery may be done to remove the thyroid.
If you have had radioactive iodine treatment or surgery, you will need to take replacement thyroid hormones for the rest of your life. This is because these treatments destroy or remove the gland.
TREATMENT OF THE EYES
Some of the eye problems related to Graves disease often improve after treatment with medicines, radiation, or surgery to treat the overactive thyroid. Radioiodine therapy can sometimes make eye problems worse. Eye problems are worse in people who smoke, even after the hyperthyroidism is treated.
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 eye drops may reduce eye irritation. In rare cases, surgery or radiation therapy (different from radioactive iodine) may be needed to prevent further damage to the eye and loss of vision.
Graves disease often responds well to treatment. Thyroid surgery or radioactive iodine often will cause an underactive thyroid (hypothyroidism). Without getting the correct dosage of thyroid hormone replacement, hypothyroidism can lead to:
- Mental and physical sluggishness
- Weight gain
- Dry skin
- Cold intolerance
- Abnormal menstrual periods in women
When to Contact a Medical Professional
Call your provider if you have symptoms of Graves disease. Also call if your eye problems or other 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
- Rapid, irregular heartbeat
- Sudden shortness of breath
Brent Wisse, MD, board certified in Metabolism/Endocrinology, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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