Thyroid conditions can be scary and overwhelming. That’s why it is important to understand everything you can about your condition. Knowing your thyroid test results is essential to the process of diagnosing and treating thyroid conditions. For a better understanding about these tests, read on and find out the various ways to check the thyroid hormone levels!
Thyroid Test Results | The Thyroid Function Tests
1. TSH Test
A thyroid stimulating hormone test measures the TSH level in your blood. The pituitary gland senses if we have sufficient thyroid hormone in our bloodstream. If the pituitary gland detects that there is not enough thyroid hormone in our bloodstream, the pituitary gland will produce TSH (thyroid stimulating hormone) to trigger the thyroid to produce its hormones. A high level of TSH means the thyroid gland is failing and could indicate hypothyroidism. On the other hand, low TSH level could mean the patient has an overactive thyroid producing too much hormone, which is called hyperthyroidism. There are certain occasions wherein a low TSH is due to an abnormality in the pituitary gland, which prevents it from producing the right amount of TSH to incite the thyroid.
The “normal range” or reference range is an essential part of an overall thyroid examination and treatment. Most of the laboratories in the United States have an official reference range for TSH tests, which runs from roughly 0.5 to 4.5 or 5.0 (µIU/L). If the TSH level is within the recommended range, the patient is referred to as euthyroid or with a normal functioning thyroid gland.
2. T4/Thyroxine and Free T4/Free Thyroxine Test
The T4 test is the most commonly used thyroid analysis of all. Most of the hormone produced by the thyroid gland is known as Thyroxine, or T4. Thyroxine is considered a storage hormone. Once in the bloodstream, it travels to the organs such as the kidneys and liver. There, T4 is then converted to its active form of triiodothyronine. A proper amount of thyroxine is vital for health because it affects almost all of the body’s system and plays a crucial role in the heart, brain development, muscle control, bone health, digestive system, and metabolism.
Total T4 measures the entire amount of thyroxine circulating in the bloodstream while Free T4 measures the available, freed amount of thyroxine in the bloodstream. The reference range for T4 is 4.2-12.5 µg/dL and Free T4 is 0.8-1.8 ng/dL. This should be the thyroid test results of a normal thyroid gland.
3. T3/Triiodothyronine and Free T3/Triiodothyronine Test
T3 tests are usually helpful to the diagnosis of hyperthyroidism and define its severity. A healthy thyroid gland provides mainly thyroxine and it is needed to be converted into triiodothyronine in order to perform its task, which is to deliver energy and oxygen to cells. The T3 test calculates the total amount of triiodothyronine circulating in the bloodstream, while Free T3 measures the unbound levels of the hormone triiodothyronine available for the body’s consumption. Patients with elevated T3 level are diagnosed with a hyperthyroid condition. The thyroid test results should have a reference range of T3 is 80-200 ng/dL for T3 and the Free T3 should have 2.3- 4.2 pg/mL.
4. Thyroid Peroxidase Antibodies
Our immune system normally defends us from foreign invaders such as bacteria and viruses by destroying them with substances called antibodies, created by blood cells known as lymphocytes. In the case of hypothyroidism, or hyperthyroidism, these lymphocytes produce antibodies against the thyroid gland. It can either stimulate or damage the gland. Thyroid Peroxidase Antibodies or TPOAb are the results of an autoimmune attack on the thyroid gland. Thyroid peroxidase plays a crucial role in the conversion of T4 to T3. So if TPOAb levels are elevated, it is clear evidence of inflammation of the gland or tissue destruction like Hashimoto’s disease.
The reference range is 0-35 IU/mL. When the TPOAb level is within the given range, patients are considered normal and less likely to have Hashimoto’s disease. TPOAb has been seen in approximately 95% of people with Hashimoto’s Thyroiditis and 50-85% of patients with Graves’ disease.
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Both normal and cancer thyroid cells produce proteins known as Thyroglobulin. A thyroglobulin testing is primarily used as a tumor marker to assess the effectiveness of the surgery done to a patient with thyroid cancer. It is also used to monitor for recurrence. It is also used to check if the cancerous tumor is producing thyroglobulin before the treatment. Having thyroglobulin in the blood is a sign that a person still has a thyroid gland after a surgery. The reference range for this thyroid test should be less than 0.1 ng/ml if the patient doesn’t have a thyroid gland. If the patient still has a gland, range should be less than or equal to 33ng/ml. Considering most of the common thyroid cancers are based on follicular and papillary produce thyroglobulin, an increase in thyroglobulin levels is often a sign of cancer recurrence.
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The thyroid has a huge role in influencing the function of the most significant organs in our body. This includes the heart, brain, liver, kidneys, and skin. In the event of a disorder, having your thyroid checked can give you an overview of how to manage it. Reference ranges vary from lab to lab so determine the specific ranges of the lab where your test was conducted. Get a copy of your thyroid test results so you can plan the best possible care for your thyroid condition.
Do you know more ways to test the levels of the thyroid hormones? Share it with us in the comments below!
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