Hyperthyroidism is also called thyrotoxicosis. It is the state in which the thyroid gland releases more than the usual amount of thyroid hormones into the blood stream. The two thyroid hormones, thyroxine and tri-iodo-thyronine, act on all the cells in the body that are consuming energy, to speed up the processes of fuel consumption. Normally, the amount of thyroid hormone in the blood is carefully controlled so that these processes occur at a correct rate. In hyperthyroidism the processes are accelerated. In most cases the gland is either generally enlarged or contains many nodules of overactive thyroid tissue.

Symptoms

Thyrotoxicosis is much more common in women than in men. The affected person appears jumpy, anxious and overactive. Typically, there are some or all of the following symptoms:-

• Constant body movement, as of severe anxiety
• A fast and sometimes irregular pulse
• Irritability
• Warm, clammy hands
• Sweating
• Shakiness
• Muscle weakness
• Tremor
• Vomiting and diarrhoea
• Scanty or absent periods
• Loss of weight in spite of good appetite and large intake
• Palpitations
• Great dislike of hot weather

Causes

There are several possible causes of hyperthyroidism. They include:

• A defect of the immune system (autoimmune disease)
• Excess iodine intake
• Thyroid gland inflammation from radiation, virus infection or autoimmune disease

Graves’ disease is the most common cause of hyperthyroidism. This disorder of the immune system is caused by abnormal antibodies that have a similar effect to the thyroid-stimulating hormone (TSH) which is created naturally in the pituitary gland. The result is over-production of thyroid hormones.

Treatment

Thyrotoxicosis is treated with antithyroid drugs, such as carbimazole and propylthiouracil, that reduce the production of thyroid hormones. Gland activity can also be reduced by using a radioactive isotope of iodine. While treatment is taking effect, many of the symptoms can be relieved by the use of beta-blocker drugs (beta-adrenergic blocking agents)

Surgery to remove all or part of the thyroid gland (known as a thyroidectomy) will permanently cure hyperthyroidism. The goal of the surgery is to remove just enough of the gland so that thyroid production is back to normal, however if too much is taken, than the individual can become hypothyroid.