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Everything you need to know about hyperthyroidism
What is hyperthyroidism?
Hyperthyroidism, or an overactive thyroid, occurs when the thyroid makes too much of the hormones, thyroxine (T4) and triiodothyronine (T3). An excess of thyroid hormones speeds up metabolism in the body.
What can cause hyperthyroidism?
Many things can lead to hyperthyroidism, with Grave’s disease which is an autoimmune disease being the most common. In Grave’s disease, the body’s immune system creates antibodies that target the thyroid and increase the production of both T3 and T4. These antibodies are called thyroid-stimulating immunoglobulins (TSIs). TSIs mimic the role of the thyroid stimulating hormone (TSH) which instructs the thyroid to produce hormones. Grave’s disease can run in families, so having a close family member with Grave’s disease increases an individual's risk of development. Like many autoimmune diseases, women are at a greater risk of developing Grave’s disease compared to men.
Other possible causes of hyperthyroidism include:
What are the symptoms of hyperthyroidism?
Hyperthyroidism causes an increase in metabolic rate which causes symptoms such as:
How is hyperthyroidism diagnosed and treated?
Often hyperthyroidism symptoms mimic the symptoms of many other conditions, because of this, hyperthyroidism is often misdiagnosed. A blood test to measure thyroid hormone and antibody levels is the best way to diagnose hyperthyroidism.
There are many ways to treat an overactive thyroid:
How are thyroid blood tests affected by hyperthyroidism?
In the most common forms of hyperthyroidism, it is the thyroid gland which is responsible for producing too much T3 and thyroxine. In these conditions, the pituitary gland is functioning normally so TSH production will be reduced. This gives the result below:
T3: High or high normal
There are rare forms of hyperthyroidism in which the pituitary gland malfunctions and produces too much TSH. So although the thyroid gland is healthy, it is overstimulated by TSH and produces too much T3 and t4. This gives the result below:
If you think that you may have hyperthyroidism, it is important to see your doctor promptly as the condition can worsen over days to weeks.