Research suggests low thyroid levels may also be linked to elevated cholesterol and blood pressure. In severe cases, the condition can lead to Graves disease (swelling and eye protrusion), changes in heart rate and pumping capacity and coma.
The Thyroid Foundation of America estimates about 8 million Americans have hypothyroidism. Women are affected more often than men. Risk increases with age. By 60, about 17 percent of women and 8 percent of men have hypothyroidism. Many people with low thyroid hormone are unaware they have the condition.
Frank Comstock, M.D., General Practice Physician, recommends three blood tests for people who have signs of a thyroid disorder: TSH, T4 and T3.
Sometimes thyroid tests show “normal” thyroid function, despite the patient having symptoms suggestive of thyroid disease. Comstock says if the blood tests are in the range of low normal or borderline normal, physicians may want to consider starting thyroid replacement therapy. The most common treatment is supplementation with T4 hormone. On occasion, patients who have trouble converting the T4 into T3 may need a combination of T4 and T3.
Not everyone agrees with thyroid replacement in patients with low or borderline low hormone levels. The American Association of Clinical Endocrinologists currently advises physicians to make treatment decisions on a case-by-case basis. Experts also warn that, in most cases, once thyroid replacement is started, it is a life-long therapy. Patients also need regular monitoring because elevated levels of thyroid hormone can lead to hyperthyroidism, while levels that drop too low could lead to a return of hypothyroidism symptoms.