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.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cold.A needle is inserted into a vein (usually in the arm inside of the elbow or on the back of the hand) and blood is withdrawn and collected in a vial or syringe.
The most common thyroid function tests. TSH - Thyroid Stimulating Hormone FT4 - Free T4 (the active part of thyroxine) FT3 - Free T3 (the active part of triiodothyronine) Other blood tests Thyroid antibodies - to check the cause and severity of the thyroid disorder.Thyroglobulin and calcitonin - to monitor people with thyroid cancer. Typical reference ranges for normal thyroids. Test From To Units TSH 0.4 4.5 mU/L (milliunits per litre) FT4 9.0 25.0 pmol/L (picomoles per litre) FT3 3.5 7.8 pmol/L (picomoles per litre) These ranges are only a guide.
On the day of the test, having your child wear a T-shirt or short-sleeved shirt can make things easier for the technician drawing the blood. The Procedure A health professional will usually draw the blood from a vein.Gcid003517 ptid1 Thyroid Function Tests. (n.d.). American Thyroid Association. Retrieved June 1, 2012, from yroid. org/patients/brochures/FunctionTests_brochure. pdf Thyroxine (T4) Test. (n.d.). Summit Medical Group. Retrieved June 1, 2012, from m/library/adult_health/thyroxine_test/ What do you think of this page?
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.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.
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.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.
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.A low TSH levels together with a low FT4 levels can indicate a disorder of the pituitary gland. Management of thyroid disorders If you have a diagnosed thyroid disorder, thyroid function tests will check that your treatment is working help to fine-tune your treatment Other points Treatment aims to get your TSH levels back within.
Newborns are routinely screened for hypothyroidism, which can cause serious medical problems if left untreated. Preparation No special preparations are needed for this test. However, certain medications, including seizure medication, cardiac drugs, steroids, birth control pills, and even aspirin can affect the results, so it's important to tell the doctor about any medication your child.The second, a free T4 test, measures only the free T4 in your blood. Why Doctors Perform a T4 Test. Your doctor will often order a T4 if a thyroid-stimulating hormone (TSH) test has come back with abnormal results and your doctor wants further insight into what could be wrong with your thyroid.
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.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.
Your health and well being are important to us. We're sorry you couldn't find the information you were looking for this time, but your comments will help us identify gaps and improve our content.The reference range for FT4 in particular does currently vary between methods and so any 'typical' reference range quot;d will be subject to method and local interpretation. Test results outside the reference range.
Reviewed by: Yamini Durani, MD. Date reviewed: July 2014.What Is a T4 Test? Your thyroid produces a hormone, thyroxine, which is known as T4. This hormone plays a role in several of your bodys functions, including growth and metabolism.
Details Information Quick Guides Thyroid function tests are currently the most accurate way to diagnose and manage thyroid disorders. Your doctor will interpret the blood test results, together with your symptoms and how you feel, to reach a diagnosis to manage your treatment.What It Is A T4 test measures the blood level of the hormone T4, also known as thyroxine, which is produced by the thyroid gland and helps control metabolism and growth.
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.After the procedure, the elastic band is removed. Once the blood has been collected, the needle is removed and the area is covered with cotton or a bandage to stop the bleeding.
We're sorry, an error occurred. We are unable to collect your feedback at this time. However, your feedback is important to us. Please try again later. Thank you for your feedback.Normal results are generally from 4.5 to 11.2 mcg/dL (micrograms per deciliter). Because T4 is not the only hormone involved in thyroid function, a normal result on this test may not mean that you do not have a thyroid problem.
Afterward, there may be some mild bruising, which should go away in a few days. Getting the Results The blood sample will be processed by a machine. The results are usually available after a few hours or the next day.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.
Risks The T4 test is considered a safe procedure. However, as with many medical tests, some problems can occur with having blood drawn. These include: fainting or feeling lightheaded hematoma (blood accumulating under the skin causing a lump or bruise) pain associated with multiple punctures to locate a vein.The T4 test is performed as part of an evaluation of thyroid function. Two blood tests may be performed as part of a T4 test: total T4, which measures the entire amount of thyroxine in the blood, including the amount attached to blood proteins that help transport the hormone through the bloodstream free T4, which.