Aging itself has only minor effects on the thyroid gland and thyroid hormones. As people get older, the thyroid gland shrinks and shifts lower in the neck. The level of the thyroid hormone triiodothyronine (T3) may fall slightly, but the speed of vital functions changes very little. However, thyroid disorders become more common with aging.
Disorders that affect thyroid function, particularly hyperthyroidism Hyperthyroidism Hyperthyroidism is overactivity of the thyroid gland that leads to high levels of thyroid hormones and speeding up of vital body functions. Graves disease is the most common cause of hyperthyroidism... read more and hypothyroidism Hypothyroidism Hypothyroidism is underactivity of the thyroid gland that leads to inadequate production of thyroid hormones and a slowing of vital body functions. Facial expressions become dull, the voice... read more , can be thought of as great masqueraders in older people. These disorders often cause symptoms that are easily mistaken for symptoms of other conditions or even as signs of getting old.
Increased or decreased thyroid function can dramatically worsen the way an older person feels and can greatly diminish the ability to carry out daily activities. For these reasons, the great masqueraders must be unmasked and recognized for what they are so that they can be effectively treated.
Some experts recommend measuring the level of thyroid-stimulating hormone in the blood in people over 70 years old every year or every few years, although a number of medical bodies that have examined this question recommend against screening truly asymptomatic adults in order to avoid over-treating people with minor laboratory abnormalities.