The T3 T4 blood test is used to help determine how well a person’s thyroid happens to be functioning. These hormones are produced by the gland and control the rate at which a person uses energy throughout the day. It is a system of feedback. The thyroid is stimulated to produce the hormones, which then get bound to proteins, and this helps people make it through their day.
There are free hormones and there are bound hormones thanks to the proteins that circulate. The T3 T4 blood test typically measures the amount of free hormones that are available. Total levels can also be measured, but the results can be somewhat misleading at times because having high protein levels in the blood can create false results. Based on the findings of this blood test, movement toward a diagnosis when there are bothersome symptoms being experienced can be had.
Why Is the T3 T4 Blood Test Ordered?
If an individual is suffering from the signs and symptoms of a thyroid disorder, then the T3 T4 blood test will be requested to determine if the hormone results are outside of a normal range. Hyperthyroidism would be associated with a high positive test result and could exhibit itself with numerous symptoms that may seem non-specific. Anxiety, trouble sleeping, and tremors in the hands are all commonly present.
There may also be a sensitivity to light, visual disturbances such as “floaters,” puffiness around the eyes, the feeling of weakness, and weight loss present. Some people may also notice frequent issues with diarrhea.
The T3 T4 blood test results may also be out of range with a low positive result. This test, along with certain physical signs and symptoms, may indicate the presence of hypothyroidism instead. Weight gain, dry and puffy skin, and unusual levels of fatigue are commonly seen with this condition. The thyroid gland may become enlarged, constipation may occur, and there may be an intolerance developed toward cold temperatures.
Women who are pregnant may have the T3 T4 blood test at the beginning and end of their pregnancy if a thyroid disorder is suspected to help monitor for complications. Thyroid screening is also a common blood test that is ordered for newborns.
What Do My Test Results Mean?
In general terms, test results for the T3 T4 blood test may be high, normal, or low. This indicates the range where specific results compare against average results. Although a diagnosis from this test is typically not received, it does provide added information for a medical provider to further investigate a thyroid condition.
Low or high T3 T4 test results that are combined with equally low or high levels of thyroid stimulating hormone may also indicate that there could be an issue with the pituitary gland.
After a diagnosis has been made, the T3 T4 blood test can also be used as a monitoring mechanism to determine if a treatment plan is effective or not. Testing levels will adjust to more normal or average rates if treatments are effective, while ineffective treatments will cause hormone levels to persist at their current levels.
Here’s What You Need to Know
An acute illness may affect test results. After a period of hospitalization or an extended illness, a medical provider may wait to begin testing to avoid having false results come back from the T3 T4 blood test.
It is also important to remember that this test result is like a photograph of current events within the body when looking at these hormone levels. The levels of free and total T3 and T4 will adjust themselves throughout the day and can be affected by numerous conditions. Having one slightly high or low test result may not have medical significance. Only a medical provider familiar with an individual’s medical history can make a determination of the significance of any one result.
Large doses of aspirin may affect the total levels of T4 and create false results. Discuss aspirin use before this blood test to determine if any lifestyle changes may be present.
Thyroid and pituitary health issues can be debilitating if they are left untreated. The T3 T4 blood test is one of the tools that medical providers will use to help determine if problems with hormone production are the cause of bothersome physical symptoms. If you have any questions about your specific condition or symptoms, use this guide to discuss what options are available to you at your next appointment with your preferred medical provider so that a treatment plan may be developed of necessary.