Hyperthyroidism is caused by the effects of too much thyroid hormone on the body.  The symptoms of hyperthyroidism usually have gradual onset so patients may not realize they are symptomatic for some time.

Persons with Hyperthyroidism may exhibit any number of the following

• Nervousness
• Insomnia
• Breathlessness
• Light or absent menstrual periods
• Fatigue
• Fast heart rate
• Trembling hands
• Staring gaze
• Insomnia
• Tiredness
• Irritability
• Unexplained weight loss or weight gain
• Heat sensitivity
• Increased perspiration
• Warm skin
• Flushing
• Itchy skin
• Fine, brittle or thinning hair
• Muscular weakness
• Eye changes
• Weak leg muscles
• Stomach upset
• Diarrhea
• Goiter (swelling of the thyroid gland)
• Protruding eyes

There are several causes of hyperthyroidism

Graves’ disease

An autoimmune disease that is the most common cause of hyperthyroidism, where the entire gland overproduces thyroid hormone. Grave’s disease can be triggered by stress, smoking, radiation to the neck, medications, and infectious organisms such as viruses. Graves’ disease is also hereditary and is up to five times more common among women than men.

Excessive intake of thyroid hormones

Patients who are currently being treated for thyroid related problems may induce hyperthyroidism by taking too much thyroid hormone medication in hopes that this will alleviate their symptoms at a faster rate.

Abnormal secretion of thyroid stimulating hormone (TSH)

In rare instances, high rates of TSH may be produced by a tumor in the pituitary gland. This causes the thyroid gland to produce excessive amounts of thyroid hormone.

Thyroiditis (inflammation of the thyroid)

May occur after a viral illness that included a fever and a sore throat. The thyroid gland becomes sensitive and the inflammation causes the thyroid to secrete excess thyroid hormone. Thyroiditis can be diagnosed by a thyroid scan.

Excessive iodine intake

An excess of iodine may cause hyperthyroidism as the thyroid gland uses iodine to make thyroid hormones. Patients who already have problems with their thyroid gland may develop iodine-induced hyperthyroidism. Some medicines used to treat heart problems, contain large amounts of iodine and may cause thyroiditis.

A single “hot” nodule (non-cancerous lump or tumor in the gland) can also produce excessive amounts of thyroid hormones.

Treatment

Treatment for hyperthyroidism is dependent on the cause and severity of symptoms. Options include.

• Antithyroid medications
• Radioactive iodine (stops excess hormone production by destroying the thyroid.
• Thyroid removal surgery

If the thyroid must be removed with surgery or destroyed with radiation, thyroid hormone replacement pills must be taken for the rest of the patient’s life.

Left untreated, hyperthyroidism may cause weight loss heart problems (rapid heart rate and heart failure) and problems replacing minerals in bones that may cause osteoporosis.

In rare instances, hyperthyroidism can lead to a condition called thyroid storm (crisis), in which the thyroid gland releases large amounts of thyroid hormones in a short period of time. Thyroid storm usually occurs after serious infection or emotional stress.