THYROID PROFILE TEST
The thyroid gland is a butterfly-shaped endocrine gland that is normally located in the lower front of the neck. The thyroid’s job is to make thyroid hormones, which are secreted into the blood and then carried to every tissue in the body. Thyroid hormones help the body use energy, stay warm and keep the brain, heart, muscles, and other organs working as they should.
The thyroid produces two major hormones: triiodothyronine (T3) and Thyroxine (T4). Where one’s thyroid gland does not produce enough of these hormones (A condition known as hypothyroidism), the person may experience symptoms such as
- Weight gain,
- Depression and
- Lack of energy.
On the contrary, if the thyroid gland produces too many hormones (known as hyperthyroidism), one may experience
- Weight loss,
- High levels of anxiety,
- Tremors, and
- A sense of being on a high.
Typically, a doctor who is concerned about thyroid hormone levels will order broad screening tests, such as the T4 or the thyroid-stimulating hormone (TSH) test. If those results come back abnormal, the doctor will most likely order further tests to pinpoint the reason for the problem.
TESTS
There are quite a few readily available blood tests to measure these hormones and which are widely used, but not all are useful in all situations.
Thyroid function tests are a group of tests performed to evaluate how the thyroid gland is functioning. Thyroid gland is located below the Adam's apple in the neck and it secretes hormones. The hormones secreted by the thyroid gland affect the way in which the various organs in the body utilize energy and also regulate the mineral levels in the blood. These tests are performed to diagnose and determine the cause of an underactive thyroid (hypothyroidism) or an overactive thyroid (hyperthyroidism) gland.
The tests included are
- TSH test - A TSH test is conducted to find out if the thyroid gland is working the way it should. It can tell if it is overactive (hyperthyroidism) or underactive (hypothyroidism). The test can also detect a thyroid disorder before any symptoms. If untreated, a thyroid disorder can cause health problems.
- T4 test - A test that measures both free and bound T4 is called a total T4 test. Other tests measure just free T4. A free T4 test is considered more accurate than a total T4 test for checking thyroid function.
- T3 test - A free or total triiodothyronine (free T3 or total T3) test is used to assess thyroid function. It is ordered primarily to help diagnose hyperthyroidism and may be ordered to help monitor treatment of a person with a known thyroid disorder. Most of the T4 and T3 circulates in the blood bound to protein, while a small percentage is free (not bound).
- Thyroid-stimulating immunoglobulin (TSI) test - Thyroid stimulating immunoglobulin or TSI for short (1) is the name of a blood test which is used to identify the presence of autoimmune disease in those with hyperthyroidism. An abnormally high level of TSI in the body is highly predictive of a condition known as Graves' disease.
- Anti-thyroid antibody test, also known as thyroid peroxidase antibody test (TPOab) - Thyroid autoantibodies are antibodies that develop when a person's immune system mistakenly targets components of the thyroid gland or thyroid proteins, leading to chronic inflammation of the thyroid (thyroiditis), tissue damage, and/or disruption of thyroid function. Laboratory tests detect the presence and measure the quantity of specific thyroid autoantibodies in the blood.
WHY THYROID PROFILE TESTS IS NEEDED
Thyroid tests are performed to:
- Diagnose hypothyroidism or hyperthyroidism
- Monitor treatment in people having thyroid disorders
- Screen new-borns for any inherited thyroid disorders
When to Avoid:
There are no specific conditions in which this test should be avoided.
However, patients must inform the doctor if:
- They are pregnant, as the levels of thyroid hormones change during pregnancy.
- They have undergone any x-ray test in the past that have used a special contrast dye, as this can affect the results of the thyroid function test.
- They are taking any medicines, as some of it can alter the test results.
CONDUCTING THE TESTS
A blood draw, also known as venipuncture, is a procedure performed at a lab or a doctor’s office. The patient will be asked to sit in a comfortable chair or lie down on a cot. He will be asked to roll up one sleeve or to remove one arm from the sleeve if he is wearing long sleeves.
A band of rubber will be wrapped tightly around the upper arm to make the veins swell with blood. Once the technician has found an appropriate vein, a needle will be inserted under the skin and into the vein. The technician will collect the blood in test tubes and send it to a laboratory for analysis.
When the technician has gathered the amount of blood needed for the tests, he will withdraw the needle and place pressure on the puncture wound until the bleeding stops. The technician will then place a small bandage over the wound.
The patient should be able to return to his/her normal daily activities immediately.
FOLLOW-UP TESTS
If the blood work suggests that the thyroid gland is overactive or underactive, the doctor may order a thyroid uptake test or an ultrasound test. These tests will check for structural problems with the thyroid gland, thyroid gland activity, and any tumors that may be causing problems. Based on these findings, the doctor may want to sample tissue from the thyroid to check for cancer.
If the scan is normal, our doctors will likely prescribe medication to regulate thyroid activity. This will be followed up with additional thyroid function tests to make sure the medication is working.
