Thyroid deficiency generally affects women who are over the age of 40, but it can also affect men and teenagers, especially if it runs in the family. Carpal tunnel syndrome has also been associated with thyroid deficiency. Hashimoto's thyroiditis is the most common form of hypothyroidism presenting with an enlarged thyroid gland that becomes nonfunctional, with the active parts of the gland deteriorating after several years. Treatment for hyperthyroidism, which includes administering radioactive iodine and surgical removal, may also result in hypothyroidism. In many undeveloped countries where there is a chronic lack of iodine in the diet, goitrous hypothyroidism resulting from an underactive thyroid gland is common.
Severe hypothyroidism is known as myxedema.
Diagnosis Overt hypothyroidism is easy to diagnose by a simple blood test. Low levels of T3 and T4 are signs that you do not have enough thyroid hormones. Also, an elevated TSH is a sign of thyroid deficiency. When your TSH is high, it means the pituitary gland is trying to make the thyroid gland produce more hormones. If, however, someone is suffering from the classic symptoms of thyroid deficiency but has normal test results, the thyroid slowdown could be slight or age related and is not easily detected by a blood test.