Hyperthyroidism occurs when the thyroid produces excess thyroid hormone. It is a common disorder affecting about 200 million people worldwide, most of whom are women. The symptoms can range from mild nervousness, weight loss and insomnia to a dangerously fast heart beat which can be life-threatening.

There are several types of hyperthyroidism, each associated with a different particular cause. The most common type is Graves` Disease (also called diffuse toxic goiter), which is possibly a genetically linked disease, caused by antibodies in the blood which stimulate the thyroid to grow and produce excess hormone. Other causes of hyperthyroidism include toxic multinodular goiter, in which individual thyroid nodule(s) are responsible for excess thyroid hormone production, a thyroid adenoma, or a single lump within the thyroid gland that takes control and overproduces thyroid hormone, and thyroiditis (inflammation of the thyroid), a self limiting disease which is possibly caused by an infection and is often associated early on with an increased release of thyroid hormone. Other rare causes include excess dietary iodine consumption, abuse of thyroid hormone medication when patients overdose on thyroid hormone pills (either accidentally or purposefully because they think it will help them lose weight – a fallacy because taking too much thyroid hormone can be dangerous and life threatening), overactive metastatic thyroid cancer, or rare diseases of the ovary or testicles that can cause the thyroid to be over-stimulated.

There are several symptoms associated with hyperthyroidism:

• Nervousness and irritability
• Increased resting heart rate causing palpitations
• Hypertension (high blood pressure)
• Heat intolerance and increased sweating
• Tremor
• Weight loss or alterations in appetite
• Frequent bowel movements
• Sudden paralysis
• Thyroid enlargement (lump in the neck)
• Pretibial myxdema: thick redness on the front of the legs (with Graves` Disease)
• Thin, delicate skin and irregular fingernail and hair growth
• Menstrual disturbances (decreased flow)
• Impaired fertility
• Mental disturbances
• Sleep disturbances (including insomnia)
• Changes in vision, eye irritation, or exophthalmos significant protrusion of the eyes due to swelling of the orbital tissues around the eyes (with Graves` Disease)

The symptoms of hypothyroidism are mainly dependent on the amount of decrease in thyroid hormone and duration of time since onset of disease. For most patients, the symptoms are mild and can often be confused with other problems. The symptoms may include the following:

• fatigue and muscle swelling or cramps (mainly in the arms and legs)
• tingling in the fingers
• loss of equilibrium
• weight gain
• dry skin and cold intolerance
• yellowish skin
• coarseness or loss of hair
• goiter (enlarged thyroid causing a lump in the neck)
• constipation
• hoarseness
• memory and mental impairment
• decreased concentration
• depression
• menstruation disturbances (irregular or heavy menstruation)
• infertility or miscarriages
• slow heart rate
• myxedema: fluid infiltration of the tissues causing puffiness (mainly in the face)

The major role of the thyroid gland is to produce thyroid hormone, which controls the metabolic rate. When the production of thyroid hormone decreases below the normal body`s need, the condition is referred to as hypothyroidism. Without enough thyroid hormone, the body becomes tired and run down. Although there are many different causes of an underactive thyroid gland, the resulting effect on the body is the same.

Many of the symptoms of hypothyroidism are very subtle and are experienced by people without thyroid disease. Thus, a lot of physicians overlook the symptoms of fatigue, weight gain and depression and attribute them to other causes. Physicians should check to see if thyroid disease is the cause of these everyday symptoms, because an underactive thyroid is very easy to treat. In addition, patients who are treated for hypothyroidism can regain full control of their lives and eliminate these symptoms entirely.


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