Health Alert WEB EXCLUSIVE: Thyroid disease

Question: What tests are used to find a thyroid problem?

Answer: Thyroid problems can be diagnosed with symptoms and simple blood tests.

Blood tests to measure TSH, T4, T3 and Free T4 are readily available and widely used. Tests to evaluate thyroid function include the following:


The best way to initially test thyroid function is to measure the TSH level in a blood sample. A high TSH level indicates that the thyroid gland is failing like in primary hypothyroidism

The opposite situation, in which the TSH level is low, usually indicates that the person is producing too much thyroid hormone (hyperthyroidism).

Occasionally, a low TSH may result from an abnormality in the pituitary gland


Combining the TSH test with the FT4 helps determine further cause and extent of Thyroid dysfunction .

The finding of an elevated TSH and low FT4 indicates primary hypothyroidism due to disease in the thyroid gland.

A low TSH and low FT4 indicates hypothyroidism due to a problem involving the pituitary gland.

A low TSH with an elevated FT4 or is found in individuals who have hyperthyroidism.


T3 tests are often useful to diagnosis hyperthyroidism or to determine the severity of the hyperthyroidism. Patients who are hyperthyroid will have an elevated T3 level.

T3 testing rarely is helpful in the hypothyroid patient, since it is the last test to become abnormal.


The immune system of the body normally protects us from foreign invaders with substances called antibodies produced by blood cells known as lymphocytes.

In many patients with thyroid problems , lymphocytes make antibodies against their thyroid that either stimulate or damage the gland.

Two common antibodies that cause thyroid problems are : thyroid peroxidase and thyroglobulin.

Measuring levels of thyroid antibodies may help diagnose the cause of the thyroid problems.