Definition & Overview
Graves’ disease is a medical condition first discovered and described in the early 19th century by Sir Robert Graves, hence its name. Over time, it has proven to be one of the most common thyroid problems and the leading cause of hyperthyroidism. Although easy to treat, the disease is hard to diagnose and has a high risk of recurrence. It can also lead to serious complications and even death when not promptly treated; otherwise, the condition rarely causes any long-term negative effects on a person’s health.
Cause of Condition
To understand the underlying cause of Graves’ disease, it is important to understand how the thyroid gland works and the crucial role it plays in the body. The thyroid gland control’s the body’s metabolism, or the speed at which the body produces energy from food intake, and for secreting hormones to help with this process. If the thyroid gland fails to work properly, it may produce either less or more of these hormones than the body requires, thus throwing the body out of balance. If the thyroid gland produces an overabundance of hormones, the patient will experience faster heartbeat, trembling, sweating, and weight loss. This hormone production process is triggered and regulated by a chemical called the TSH or thyroid-stimulating hormone, which is released by the pituitary gland, another gland located in the brain.
Graves’ disease occurs when the body’s immune system malfunctions and causes the release of abnormal antibodies that copy the role of the TSH chemical. The antibodies will then produce false signals that cause the thyroid gland to produce excessive amounts of hormones. It is not known what exactly triggers the production of these antibodies, but studies show that heredity, environmental factors, and stress may play a role. Two other possible causes are pregnancy and an infection, although such cases are very rare.
Women are also found to have a higher susceptibility to this malfunction, and so are smokers. Although the disease can affect people of all ages, the risk is greatest between the ages 20 and 30. Existing autoimmune problems may also raise a person’s risk of developing this disease. Common autoimmune disorders include vitiligo, rheumatoid arthritis, Addison’s disease, type 1 diabetes, pernicious anemia, and lupus.
The most common symptoms of Graves’ disease include:
- Enlarged thyroid, also known as a goiter
- Difficulty sleeping
- Hand trembling or tremors
- Excessive sweating
- Increased sensitivity to heat
- Rapid heartbeat
- Brittle hair
- Bowel movement that is more frequent than normal
- Difficulty becoming pregnant
- Muscle weakness
- Irregular menstrual periods
When manifesting in a smoker, the disease is more likely to cause more severe symptoms, including eye problems. Eye problems linked with Graves’ disease may cause inflamed eye muscles and tissues, causing the eyeballs to protrude from the eye sockets in a condition known as exophthalmos. It is not yet clear how the disease and this specific complication concerning the eyes are linked, and there does not seem to be any relationship between the severity of the disease and the extent of protrusion of the eyeball. The more severe the protrusion, the greater the risk a person faces of getting an infection in the affected eye, as the more protruded the eyeballs are, the less protection they get from the eyelids. In the most severe cases, the condition may cause tremendous pressure on the optic nerve and may lead to partial blindness. Fortunately, exophthalmos affects only a small percentage of all patients suffering from Graves’ disease.
Some patients suffering from Graves’ disease may also experience pretibial myxedema, a condition that causes a reddish lump on the skin, usually on the shins or on top of the feet. The skin condition is not serious and is not known to cause pain.
Graves’ disease is usually diagnosed using:
Thyroid function tests – This is a blood sample test that checks for levels of the thyroid hormone and the TSH in the blood. If the T4 is high but the TSH is low, this points to an overactive thyroid.
Radioactive iodine uptake – Since the thyroid uses iodine to make the thyroid hormone, a high iodine uptake is an indicator of Graves’ disease.
Antibody tests – Certain antibodies suggest the existence of Graves’ disease, so a patient’s blood sample may be tested for these antibodies.
These lab tests may not be conclusive, which is why doctors usually combine them to make an accurate diagnosis. Another challenge to properly diagnosing the condition is the similarity between the symptoms of Graves’ disease and those of pregnancy, which may make it hard for doctors to diagnose the disease in pregnant women.
Who to See & Types of Treatments Available
Patients experiencing the above symptoms may consult their general physician, family doctor, or internal medicine doctor. If Graves’ disease is confirmed, the patient may be referred to a specialist dealing with thyroid diseases or an endocrinologist.
Treatment for Graves’ disease comes in three types:
Surgery – The most effective treatment for Graves’ disease is the surgical removal of the thyroid. This is a safe procedure that is often prescribed for the treatment of overactive thyroids. However, since the thyroid hormones play a key role in the body, the patient has to take thyroid hormone supplements to replace the thyroid hormone that the body can no longer produce.
Antithyroid medication – There are medications that inhibit the excessive production of the thyroid hormone. There are currently two drugs in use for this purpose, namely methimazole (MMI) or propylthiouracil (PTU). MMI is the safer drug of choice for pregnant patients. These drugs can only be used for up to 2 years. In some cases, thyroid function becomes normal even when the drug intake is stopped. However, there are cases where hormone production spikes right up after the medication is ceased.
Radioactive iodine – RAI is a form of iodine that gives doses of radiation to cause some slight damage to the thyroid. When this happens, the thyroid will produce less hormones. RAI is a commonly used treatment for Graves’ disease and is not known to have harmful effects on the body.
Beta-blocker – Some doctors also prescribe beta-blockers, which block the action of the hormones, instead of blocking their production. This means that even if the thyroid continues to produce excessive amounts of hormones, the hormones won’t wreak as much havoc in the body. This is effective in relieving the symptoms experienced by Graves’ disease patients. This is, however, only used as a secondary treatment and is helpful in keeping patients comfortable and feeling well while waiting for the primary treatment to work.
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Mandel SJ, Larsen PR, Davies TF. Thyrotoxicosis. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM. Williams Textbook of Endocrinology. 12th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 12.