Hyperthyroidism, also known as overactive thyroid, is a condition in which your thyroid gland makes and releases more thyroid hormone than your body needs. In contrast, hypothyroidism, or underactive thyroid, is a condition in which the thyroid gland does not create enough thyroid hormone.
Thyroid hormones regulate our metabolism and while a lack of them causes our body functions to slow down, an excess can cause a lot of things in your body to speed up. With treatment, you can lead a healthy life but without treatment, hyperthyroidism can lead to serious heart problems, bone problems such as osteoporosis and a dangerous condition called thyroid storm.
Women are between five and ten times more likely to develop the condition than men.
Causes of Hyperthyroidism
- Graves’ disease is the most common cause and is an autoimmune condition whereby the body’s immune system creates an antibody that causes the thyroid gland to make an excessive amount of thyroid hormone. Graves’ disease can run in families and is most common in women aged 20-40. Symptoms of Graves’ disease include double vision, sensitivity to light and tearing (excessive production of tears).
- Nodules in the thyroid gland can develop and affect the regular function of the gland.
- Thyroiditis causes the gland to swell, leaking thyroid hormone into the bloodstream.
- Excessive iodine intake can cause the gland to produce too much of the thyroid hormones thyroxine (T4) and triiodothyronine (T3).
- Intake of thyroid hormone medication can be a problem if too many doses are taken.
- Certain medications used to treat heart problems contain a large amount of iodine. One such example is amiodarone which is prescribed for atrial fibrillation.
Signs and Symptoms of Hyperthyroidism
- A swelling in the neck called a goiter occurs in most people with the condition
- Irregular and rapid heartbeat, sometimes with palpitations
- Shakiness and muscle weakness especially in the thighs and upper arms
- Anxiety, nervousness and irritability
- Increased bowel movements and more frequent urination
- Weight loss despite increased appetite
- Eyes that bulge out especially in patients with Graves’ disease
- Hair changes including thinning, brittleness and alopecia
- Rapid fingernail growth
- Excessive sweating
- Extreme tiredness
- Shaky, trembling hands and redness on the palms
- Loss of interest in sex
How is Hyperthyroidism diagnosed?
If you have any of these symptoms of an overactive thyroid you should make an appointment with your GP. It is important to note that these symptoms could be due to other medical conditions and disorders. Your doctor will ask about your symptoms and carry out a physical examination.
They will also order a blood test known as a thyroid function test. This will check for levels of thyroid-stimulating hormone (TSH), thyroxine and triiodothyronine. If your test results are abnormal, your doctor may also send you for a thyroid ultrasound to check for nodules or inflammation. In some cases, a special diagnostic scan is made using radioactive iodine called a radioactive iodine update test (RAIU).
What are the treatment options?
- Anti-thyroid drugs (Such as thionamides including carbimazole and methimazole) This type of medication prevents the thyroid gland from producing excess amounts of thyroxine or thriiodothyronine.
- Radioactive iodine. The dose of radioactivity is very low and is not harmful but the overactive thyroid cells quickly absorb this iodine and soon die. It may take a few months for the therapy to relieve the symptoms and a second dose may be needed. Patients will develop an underactive thyroid and will need thyroid hormone supplements for the rest of their lives. This therapy is not suitable during pregnancy.
- Surgery. This involves removing all or part of the thyroid and is suitable for pregnant women or when other therapies are not suitable. Most people will then need thyroid hormone replacement medication for the rest of their lives.
- Beta-blockers. These medicines will slow down the heart rate but will not lower the thyroid hormone levels.
Complications can occur if the condition is untreated and can lead to congestive heart failure, miscarriage, irregular heart rhythm, osteoporosis and bone fractures.
In extreme circumstances, if symptoms suddenly worsen, it is vital to seek immediate medical attention to avoid what is known as a thyroid storm. This uncommon reaction can be triggered by an infection, injury or trauma and is life threatening requiring immediate medical treatment as it can cause severe dehydration and heart problems.
In conclusion, thyroid disease can, with proper care, be easily diagnosed and treated. It is vital that patients adhere to the treatment guidelines given to them, to ensure effective and long term relief.
If you would like more help and advice, you may like to visit the website of the British Thyroid Foundation.
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