Testing free T4 levels help doctors and other health care professionals to evaluate one’s thyroid function and to diagnose hyperthyroidism and hypothyroidism. The original test, a basic T4 test, was used for many years, but had several faults. It was easily manipulated by the amount of protein one had in his or her blood, making readings less than accurate. The new free T4 test does not have this sensitivity issue, and thus it’s readings are much more reliable. If a doctor insists on taking the old T4 test, it is a good idea to ask to have one’s free T4 evaluated or to at least gain an understanding of why this doctor prefers the old test. Though there is some amount of date on the validity of all of these tests, most doctors today agree that testing one’s free T4 is the best route to take.
In almost all cases, doctors will perform a free T4 tsh test at the same time as the free T4 evaluation. The combination of these two tests help a doctor to determine thyroid hormone functionability, to determine whether one is suffering from hyperthyroidism or hypothyroidism, and to discern what is causing the present problems. Together, these tests may also be used to evaluate a goiter patient, diagnose infertility in women, or to test a newborn baby for congenital hypothyroidism. If one has never had thyroid problems and is unsure of to why this test is being performed, one can ask a doctor for more information. As research continues and furthers itself, these tests are being used in more and more cases and conditions.
The readings of one’s test may be confusing or difficult to understand, but they are actually quite straightforward. It is safe to say that anything in the range of 0.9 ng/dL to 2.0 ng/dL is in the normal free T4 range and should not be cause for concern. If one’s levels are higher or lower than average, the patient should talk with his or her doctor to understand appropriate treatment options. A high level, anything over 2.0 ng/dL, may indicate hyperthyroidism, while a very low to low score may indicate hypothyroidism. One should be sure that his doctor keeps him informed about these scores.
It is important to understand, however, that these numbers alone do not constitute a diagnosis in themselves. Sometimes additional readings or other types of tests will be necessary for a doctor to make an accurate diagnosis. Pituitary gland conditions or a simple temporary thyroid condition may be to blame. External factors that may affect results or cause an inaccurate reading may include taking certain types of medication, undergoing estrogen therapy, beginning birth control, or even taking a large aspirin dosage. For this reason, it is very important that a doctor be informed of any medication a patient is taking. A patient should also be sure to ask whatever questions he or she needs to in order to understand his or her free T4 levels.