The Thyroid Profile Total (T3, T4 & TSH) offers a series of blood tests that measure the levels of thyroid hormones in the blood. Together, these tests help identify how well your thyroid gland works. It includes tests for thyroid-stimulating hormone (TSH), thyroxine hormone (T4)- total, and triiodothyronine hormone (T3)- total.

The thyroid gland is a butterfly-shaped organ located in the neck and produces hormones like thyroxine (T4) and triiodothyronine (T3), which are responsible for regulating metabolism and other bodily functions. The production and release of these hormones are controlled by the thyroid-stimulating hormone (TSH), which is produced by the pituitary gland.

The Thyroid Profile Total (T3, T4 & TSH) assesses the health of your thyroid gland and aids in the diagnosis and management of thyroid disorders, such as an overactive thyroid gland (hyperthyroidism) or an underactive thyroid gland (hypothyroidism). Your doctor may advise this test if you show any symptoms suggestive of hyperthyroidism, such as weight loss, nervousness, irritability, increased sweating, and rapid heartbeat, or hypothyroidism, such as weight gain, fatigue, sensitivity to cold, constipation, and dry skin. This test is also recommended for women during pregnancy to check if they have adequate amounts of thyroid hormones, as these hormones are necessary for the healthy development of babies.

Total T3 & T4 concentrations are also altered by physiological or pathological changes in thyroxine binding globulin (TBG) capacity, TBG being the transport protein responsible for binding to and transporting thyroid hormones to the necessary tissues. TSH may show marked fluctuations in an individual due to a number of factors, one of which is the time of the day when it is measured. So, the daytime testing for TSH measurements is usually preferred. 

No special preparations are needed for this profile. Usually, you do not need to stop taking your thyroid medication before taking this test. However, let your doctor know about all the medications you take as some of them can affect thyroid function.

Test result ranges are approximate and may differ slightly between different labs depending on the methodology and laboratory guidelines. The test results will help your doctor determine your medical condition, make recommendations for lifestyle modifications such as diet and exercise, decide whether or not medication will be required to manage your condition, and formulate your overall treatment plan.