Some thyroid disorders include: hyperthyroidism (overactive thyroid) hypothyroidism (underactive thyroid) hypopituitarism (underactive pituitary gland) thyrotoxic periodic paralysis (occasional muscle weakness caused by high levels of thyroid hormone) Your doctor might suspect that one of these thyroid conditions is present if you have symptoms such as: eye issues, such as dryness, irritation, puffiness, bulging skin dryness.
For example, an overactive thyroid, called hyperthyroidism, is typically associated with symptoms like weight loss, a fast heart rate, and sweating. An underactive thyroid, called hypothyroidism, may cause symptoms such as weight gain, fatigue, and feeling cold.
In some cases, your doctor might perform one or more of these tests to help assess whether a known thyroid issue is improving. Preparing for the T4 Test Quite a few drugs can interfere with your T4 levels, so its important to tell your doctor what medications youre taking.
Abnormally low levels of T4, on the other hand, may indicate the following: dietary issues, such as fasting, malnutrition, too little iodine medications that affect protein levels hypothyroidism illness Find an internist or an endocrinologist near you.
For an infant, the blood may be obtained by puncturing the heel with a small needle (lancet). If the blood is being drawn from a vein, the skin surface is cleaned with antiseptic, and an elastic band (tourniquet) is placed around the upper arm to apply pressure and cause the veins to swell with blood.
Adult g/dL Pregnancy 1st Trimester g/dL 2nd Trimester g/dL 3rd Trimester g/dL All Trimesters Together g/dL Clinical Significance. Thyroxine (T4) is the major secretory hormone of the thyroid. Only 0.03 of T4 is unbound and free for exchange with tissues.
For example, your T4 results could fall into a normal range but your T3 results could be elevated. What Do Abnormal T4 Test Results Mean? Successfully interpreting an abnormally high or low result in the T4 test often involves incorporating the results of tests for T3 and thyroid stimulating hormone (TSH) levels.
These are not the only drugs that can affect your results. Make sure to tell your doctor about every medication you use. The T4 Test Your healthcare provider will collect your blood into a tube or vial and send it to a lab for testing.
It also may help if your child looks away when the needle is being inserted into the skin. If You Have Questions If you have questions about the T4 test, contact your doctor.
My Recent Searches No Recent Search. My Tests Viewed No Test Viewed. Test Name. Overview Ordering Info Algorithms Related Guides CPT Code(s) 84436. Methodology Immunoassay Reference Range(s) Pediatric 1-8 Years g/dL 9-13 Years g/dL 14-17 Years g/dL Conversion Factor: 1 g/dL 12.9 nmol/L.
More commonly, you may experience pain or discomfort during the blood draw. You might also bleed slightly after the needle is removed, and you might develop a small bruise around the puncture site.
For example, the levels of T3 in your blood might help shed light on the situation. Elevated T4 levels might indicate: hyperthyroidism, such as iodine-induced hyperthyroidism or Graves disease (an autoimmune disease that causes hyperthyroidism) other thyroid problems, such as thyroiditis (inflammation of the thyroid gland) or toxic multinodular goiter (an enlarged thyroid gland with.
Risks of the T4 Test The T4 test has no specific risks. Risks include those present whenever you have your blood drawn. In rare cases, you might experience a serious complication such as an inflamed vein, an infection, or excessive bleeding.
Helping Your Child Having a blood test is relatively painless. Still, many kids are afraid of needles. Explaining the test in terms your child can understand might help ease some of the fear.
An abnormal result on this test alone may not give your doctor enough information to fully understand or diagnose your condition. Pregnancy can affect your T4 levels. If your T4 levels are abnormal but you are pregnant, your doctor may order further testing.
Article Resources Article resources Blood Test: T4 (Thyroxine). (2011, April). KidsHealth. org. Retrieved June 1, 2012, from ml T4. (2012, April 18). Lab Tests Online. Retrieved June 1, 2012, from http labtestsonline.
There are two kinds of T4 tests. The first, known as a total T4 test, measures both kinds of T4 (the T4 that has bonded to protein and the free T4) in your blood.
You may need to stop taking certain drugs temporarily before the test to help ensure accurate results. Medications that can affect your T4 levels include: drugs including hormones, such as androgen, estrogen, birth control pills drugs designed to affect your thyroid or treat thyroid conditions some drugs designed to treat cancer steroids.
In general, high T4 results may indicate hyperthyroidism and low T4 results may indicate hypothyroidism. However, in order for doctors to diagnose the specific type of thyroid problem, a more complete picture is obtained by performing the T4 test with other thyroid tests, such as those that measure thyroid-stimulating hormone (TSH T3 (triiodothyronine and thyroid.
A needle is inserted into a vein (usually in the arm inside of the elbow or on the back of the hand) and blood is withdrawn and collected in a vial or syringe.