Signs and Symptoms of Thyroid Problems and Blood Tests for the Condition

The thyroid gland produces hormones that regulate body metabolism. An estimated 20 million people in the United States have thyroid disease, according to the American Association for Clinical Chemistry (AACC). There are many thyroid disorders, but the most common problems are hypothyroidism (underactive thyroid), hyperthyroidism (overactive thyroid) and thyroid cancer. To properly diagnose thyroid problems, a doctor may order blood tests based on the patient's symptoms.

Hypothyroidism

• Symptoms of hypothyroidism include fatigue, sensitivity to the cold, constipation and dry, flaky skin. The thyroid stimulating hormone (TSH) test is commonly used to diagnose hypothyroidism. When the thyroid gland is underactive, the pituitary gland increases TSH levels in an attempt to stimulate thyroid hormone production. Someone with hypothyroidism will show increased levels of TSH. Another blood test used to identify hypothyroidism measures the level of T4 (thyroxine). Low T4 results point to an underactive thyroid

Hyperthyroidism

• Individuals with overactive thyroids may experience tremors, increased sweating, rapid heart rate, enlarged thyroid glands, puffiness of the eyes, fine hair and skin that is warm, excessively moist and unusually smooth in texture (due to increased blood flow and sweat production). TSH and T4 tests are also used to identify hyperthyroidism. A patient with hyperthyroidism will exhibit low TSH levels and high T4 results. An additional test is sometimes used to diagnose an overactive thyroid. The T3 test measures triiodothyronine levels in the patient's blood; someone with hyperthyroidism will have increased levels of T3 hormones.

Hashimoto's Thyroiditis

• Most cases of hypothyroidism are caused by an autoimmune disorder called Hashimoto's thyroiditis, a condition where the body attacks the thyroid gland and produces antibodies which damage and cause inflammation of the thyroid; inadequate hormone production is characteristic of Hashimoto's thyroiditis. Hashimoto's sufferers may show symptoms such as fatigue, dry skin, constipation and cold sensitivity. Thyroid antibodies tests are usually administered to diagnose this condition. This test looks for the presence of thyroid antibodies; however, it is not particularly accurate and is usually ordered along with T4 and TSH tests to aid in proper identification of the problem.

Graves' Disease

• Graves' disease is the leading cause of hyperthyroidism; it is also an autoimmune disorder where the body attacks the thyroid gland, resulting in inflammation and damage. An overproduction of thyroid hormones results in physical symptoms of hyperthyroidism. The same thyroid antibody test given to diagnose Hashimoto's thyroiditis is also given to those that may have Graves'. T3, T4 and TSH tests are also used to diagnose Graves' disease.

Thyroid Cancer

• Signs that may indicate thyroid cancer include the development of a nodule (lump) at the front of the neck, swollen lymph nodes in the neck, pain in the throat or neck, hoarseness in speaking and difficulty swallowing or breathing. A thyroglobulin test can confirm whether a patient has thyroid cancer or another condition. Thyroglobulin is a protein made exclusively in thyroid cells; a detectable or increased amount of thyroglobulin in the blood strongly suggests a tumor is present.