A few drops of blood taken from a newborn can show whether the baby has a thyroid abnormality. If blood tests reveal a problem, physicians can take corrective measures. Lacking sufficient thyroid hormones, a child may become physically and mentally retarded, a condition called cretinism. Hence, babies are usually tested just days after birth.
    Thyroid impairment may be the result of a diet poor in iodine, physical or mental stress, genetic defects, infections, disease [usually autoimmune disease], or side effects of medications prescribed for various       illnesses. An enlarged thyroid, or goiter, may be an indication of disease. The enlargement may be diffuse or in the form of nodules. Although genetically benign goiters should always receive medical attention, for they might indicate a more serious condition, such as cancer.
    Just as the accelerator controls the speed of a car’s engine, thyroid hormone regulates the rate of the body’s metabolism- chemical activity in cells that produces energy and new tissue. Thus, thyroid hormones promote normal tissue growth and repair, effect cardiac rate, and maintain the production of energy for muscles and body heat. Usually, ailing thyroids produce either too much or too little hormone. Overproduction is called hyperthyroidism; underproduction, hypothyroidism. Thyroid disease can develop gradually and imperceptibly, so one may have it for years and not know it. As with most illnesses, the outcome may be better if the diagnosis is made early.
   The more common thyroid ailments are Hashimoto’s thyroiditis and Graves’ disease. Both are autoimmune disorders- so named because the immune system attacks normal body cells, viewing them as foreign tissue. Hashimoto’s thyroiditis is six times more common in women than in men and it usually result in hypothyroidism. Grave’ disease is eight times more common in women and generally causes hyperthyroidism. If a medical examination suggests an underactive thyroid, tests for antibodies that attack the gland are usually ordered. On the other hand, if the test indicates an overactive thyroid, a thyroid scan is usually obtained, provided that the patient is not pregnant or breast-feeding.
  Hyperthyroidism usually cause excessive agitation, unexpected weight loss, rapid heartbeat, increase in bowel movements, irregular menstrual periods, irritability, anxiety, mood swings, protruding eye-balls, muscular weakness, insomnia, and thin, brittle hair.
  Hypothyroidism can lead to physical and mental sluggishness, unexpected weight gain, hair loss, and constipation, exaggerated sensitivity to cold, irregular menstrual periods, depression, voice change [hoarseness or low voice], memory loss, and tiredness.
   Proper nutrition can help to prevent thyroid problems. For example, does your food include sufficient iodine, which is essential for the production of thyroid hormone. Saltwater fish and other seafood are excellent sources of this vital element. The amount of iodine in vegetables and meats varies according to the chemical composition of the local soil. To compensate for a lack of the element in the food, some governments require that iodine be added to table salt.
  Also important to the thyroid is selenium. This trace element is part of the enzyme that transforms the hormone T4 intoT3. Again, the concentration of selenium in vegetables, meats, and milk depends on the soil. Seafood and Brazil nuts are rich sources of selenium. Of course, if you suspect that you have a thyroid problem, consult your doctor; do not try to treat it yourself.