The thyroid gland is part of the endocrine system. It’s a butterfly-shaped organ located at the base of the neck. It has many functions, including the release of hormones to control the body’s metabolism or how energy is used.
The thyroid gland hormones have many uses, including the regulation of the heart rate, breathing, body weight, muscle strength, central and peripheral nervous systems, menstrual cycles, cholesterol levels and the body temperature.
The thyroid gland produces, store and release hormones called the thyroxine (T4) and triiodothyronine (T3) into the bloodstream. These hormones reach the cells of the body to influence their functions.
The levels of these hormones should be balanced, neither too low or too high. There are two glands which help maintain the levels of these hormones – the pituitary gland and the hypothalamus. The hypothalamus is responsible for producing the thyroid stimulating hormone (TSH) releasing hormone (TRH) that tells the thyroid gland to release less or more of the T3 and T4 hormones. The hypothalamus influence the production by releasing a hormone called thyroid stimulating hormone (TSH).
If something goes wrong in the thyroid glands that may lead to an underactive or overactive thyroid, the metabolism either revs up too high or slow down. When there is an overactive thyroid, it’s called hyperthyroidism. On the other hand, an underactive thyroid is called hypothyroidism.
Thyroid diseases are serious and often life-threatening. However, they are manageable, preventable and treatable, especially if they’re detected early on.
A type of hyperthyroidism is Graves’ disease. This is an immune system disorder that leads to the overproduction of thyroid hormones. This is one of the most common causes of hyperthyroidism.
The term “Graves’ disease” was coined because the disease was named after the doctor who first described this disorder, Robert J. Graves. He first observed the disease in a patient in 1835.
According to the National Institutes of Health (NIH), Graves’ disease affects about 2 to 3 percent of the population or an estimated 10 million people. It’s five to ten times more common in women than in men.
A person with Graves’ disease may have the following symptoms, including:
- A fine tremor of the hands
- Unexplained weight loss
- Insomnia (difficulty sleeping)
- Heat intolerance or profuse sweating
- Palpitations and increased heart rate
- Chest pain
- Difficulty of breathing
- Increased stool frequency (with or without diarrhea)
- Irregular menstrual periods
- Erectile dysfunction and reduced sex drive
Other Physical Symptoms:
Goiter – A person with Graves’ disease may develop goiter if the condition is left untreated. The physical signs and symptoms of a goiter include the enlargement of the thyroid gland, coughing, difficulty in swallowing and sleep disruption.
Skin Thickening – Some individuals who have Graves’ disease may develop a thick skin on the shin or the front area of the lower leg. This skin condition is called Graves’ dermopathy or pretibial myxedema.
Eye Problems – Individuals with Graves’ disease may have eye problems, ranging from mild to severe. The less severe problem includes having red eyes, a feeling of sand or dust in the eye and tearing. More severe symptoms include eye protrusion from the eye sockets, also dubbed as Graves’ ophthalmopathy. The medical term for this eye problem is exophthalmos.
Graves’ disease is an autoimmune disease. This means that the disease is triggered by a process in the immune system. The immune system normally protects the body from foreign bodies and invaders from pathogens – bacteria and viruses. However, when a person has autoimmunity, the immune system regards the body’s healthy cells as harmful. Thus, they attack the healthy cells.
In Graves’ disease, there is a problem in the immune system, but the reason behind this is still unclear. However, the body produces an antibody to one part of the cells in the thyroid gland. These antibodies, called the thyrotropin receptor antibodies (TRAb) or thyroid stimulating immunoglobulins (TSI), cause the cells to work overtime. This happens because the antibodies trigger the cells to overproduce thyroid hormones, leading to hyperthyroidism or an overactive thyroid.
Many researchers are still in the process of investigating the triggers of this autoimmune response. Some studies have shown the link between Graves’ disease and family history, since the disease may have a genetic link.
Cause of Graves’ ophthalmopathy
Graves’ ophthalmopathy comes from the accumulation of some carbohydrates in the muscles in the area behind the eyes. The exact cause is still unknown, but some studies have linked autoimmunity to this condition.
The eye problem can cause the eyeballs to protrude from the sockets. This is one hallmark sign of Graves’ disease. However, not all patients with the condition may experience this problem.
The exact cause of autoimmune diseases is still unknown. However, many factors may increase the risk of developing Graves’ disease, including:
Family history – Graves’ disease can be seen among family members. This is a known risk factor for the disease and it’s believed to be linked to genes that can make a person susceptible to the condition.
Gender – Graves’ disease is seen more in women than in men.
Autoimmune diseases – People with other autoimmune diseases such as rheumatoid arthritis, and type 1 diabetes are more likely to develop Graves’ disease.
Age – The illness can be seen in younger, particularly those who are 40 years old and below.
Stress (Emotional and Physical) – Some stressful events in a person’s life may lead to the development of the disease. This happens to people who are genetically vulnerable to Graves’ disease.
Smoking – Tobacco or cigarette smoking can greatly affect the immune system. This can lead to the development of Graves’ disease. Smoking also increases the tendency of having Graves’ ophthalmopathy.
Pregnancy – Pregnant women who are genetically susceptible to the disease may have an increased risk of Graves’ disease.
Prolonged Graves’ disease may lead to various complications like:
Heart disease – Graves’ disease may lead to possible complications associated with the heart. Some heart diseases may develop including congestive heart failure as a result of the inability of the heart to pump adequate blood throughout the body.
Pregnancy problems – The potential complications of Graves’ disease include pregnancy issues like poor fetal growth, preeclampsia, maternal heart failure, preterm labor or birth, miscarriage and fetal thyroid dysfunction.
Thyroid storm – This is one life-threatening complication of Graves’ disease, which involves the abrupt increase in thyroid hormones. Thyroid storm is a rare but potentially-fatal condition also known as thyrotoxic crisis.
The sudden increase of thyroid crisis may lead to severe weakness, seizures, irregular heartbeat, jaundice, severe low blood pressure, fever, profuse sweating, vomiting, diarrhea, delirium, and coma. This condition needs immediate and emergency care.
Brittle bones – Graves’ disease may lead to the development of osteoporosis, a condition characterized by weak and brittle bones.
There are many ways to diagnose Graves’ disease. You need to visit a physician to have a complete physical exam and other diagnostic tests.
Physical exam – The first step is a complete physical exam with a medical history interview. The doctor may check your thyroid glands, get your vital signs like the pulse rate and blood pressure, and observe other signs of the disease like protruding eyes or tremors.
Blood tests – The doctor may also request for some blood tests to determine the hormone levels in the body. The test will reveal the levels of three important hormones of thyroid function – thyroid stimulating hormone (TSH), triiodothyronine (T3) and thyroxine (T4).
Another blood test may be requested to examine the presence of anti-thyroid antibodies. These are commonly seen in people with Graves’ disease. A test, called erythrocyte sedimentation rate (ESR), may also be recommended to check for inflammation in the body. People with Graves’ disease may have inflamed thyroid glands.
Ultrasound – An ultrasound is recommended to produce images of the thyroid gland. In this test, the doctor can see if the thyroid gland is enlarged.
Radioactive iodine uptake – Also called a thyroid scan, this test involves the injection of a small amount of radioactive iodine and using a scanning camera to get a clear view of the structure. Also, the body needs iodine to produce thyroid hormones, so the substance can help doctors determine the rate at which the gland takes up iodine.
Imaging tests – Imaging tests are used to produce images of the thyroid gland such as CT scan and magnetic resonance imaging (MRI).
The major treatment options for Graves’ disease include medications, radioactive treatment, and surgery.
The medicines used to treat Graves’ disease are called thionamides, which stops the thyroid from producing excess hormones. Once the thyroid hormone levels are controlled, the dose can be gradually tapered and stopped.
Radioactive iodine therapy
Radioactive treatment involves the use of radioactive iodine. Since the thyroid needs iodine to make hormones, the radioiodine goes into the thyroid cells and destroy the overactive cells over time. This can reduce the number of hormones the thyroid gland can produce.
Surgery can help remove the part of the thyroid or the whole gland to treat Graves’ disease. This treatment method is recommended if the thyroid gland is inflamed, there are severe eye problems that resulted from the overactive thyroid, the symptoms came back after all treatments have been done and the patient isn’t allowed to undergo the other options.