T3 & T4 Total near me in Howrah

Triiodothyronine (T3) Total Test measures the total levels (both free and bound forms) of Triiodothyronine (T3) hormone in the blood.

The thyroid gland secretes the following hormones:

• Triiodothyronine (T3)

• Thyroxine (T4)

Thyroid Stimulating Hormone (TSH) is a hormone secreted into the blood by a gland present in the brain (Pituitary gland) and it tells your thyroid gland to make and release the thyroid hormones (T3 & T4) into your blood. The thyroid gland uses iodine from food to make the thyroid hormones.

The thyroid hormones are essential for growth and metabolism. If the thyroid gland produces very high amounts of these hormones (T3 and T4), you may experience symptoms of weight loss, rapid heartbeat, tremors, sweating, anxiety, increased sensitivity to heat etc. and this is known as Hyperthyroidism.

Also, the decreased production of thyroid hormones (T3 and T4) results in Hypothyroidism which may cause symptoms like weight gain, fatigue, slow heart rate, increased sensitivity to cold, depression, dry and thin hair etc.

There is a feedback system in the body to maintain stable amounts of the thyroid hormones (T3 and T4) in the blood. When thyroid hormone levels decrease, the pituitary gland is stimulated to release TSH. This high TSH in turn leads to the release of more thyroid hormones (T3 & T4) from the thyroid gland and vice-versa.

Majority of the T3 hormone is formed from T4 hormone and a smaller fraction is produced directly by the thyroid gland. T3 hormone circulates in the blood in two forms:

1) Bound form - It is bound to proteins present in blood and this prevents it from entering body tissues. The two main proteins in the blood that the T3 hormone is bound to are albumin and Thyroxine-binding globulin (TBG), also called Thyroid hormone Binding Globulin (THBG).

2) Free form - It enters the body tissues where it is needed and this is the active form. Free Triiodothyronine (FT3) constitutes only 0.3% of the total T3 hormone.

The total T3 includes both bound and free forms circulating in the blood and can be affected by the amount of protein available in the blood to bind to them. The T3 hormone can be measured as Free T3 or Total T3. Triiodothyronine (T3) Total Test measures the total levels (both free and bound forms) of Triiodothyronine (T3) hormone in the blood and is usually done as a part of the Thyroid Profile Total test which includes two more tests: Thyroid Stimulating Hormone (TSH) and Thyroxine Total (T4) hormone.

Thyroxine (T4) Total test measures the total levels (both free and bound forms) of Thyroxine hormone (T4) in the blood.

The thyroid gland secretes the following hormones:

• Triiodothyronine (T3)

• Thyroxine (T4)

Thyroid Stimulating Hormone (TSH), also called Thyrotropin is a hormone secreted into the blood by the pituitary gland (a gland present in the brain). It directs the thyroid gland to produce and release the thyroid hormones (T3 & T4) into your blood. The iodine from the food stimulates the thyroid gland to make the thyroid hormones.

The thyroid hormones regulate growth and metabolism. If the thyroid gland produces very high amounts of these hormones (T3 and T4), symptoms of weight loss, rapid heartbeat, tremors, sweating, anxiety, increased sensitivity towards heat, etc occurs. This is known as Hyperthyroidism.

The decreased production of thyroid hormones (T3 and T4) results in Hypothyroidism which may lead to weight gain, fatigue, slow heart rate, increased sensitivity towards cold, depression, dry and thin hair, etc.

There is a feedback system in the body to maintain stable amounts of the thyroid hormones (T3 and T4) in the blood. When the levels of thyroid hormones decrease, the pituitary gland is stimulated to release TSH. High TSH, in turn, increases the release of thyroid hormones (T3 & T4) from the thyroid gland and vice-versa.

T4 hormone constitutes about 90% of thyroid hormones and circulates in the blood in two forms:

1) Bound form - It is bound to the proteins present in blood and this prevents it from entering the body tissues. The three main proteins in the blood that the T4 hormone is bound to are albumin, transthyretin and Thyroxine-binding globulin (TBG). TBG is also called Thyroid hormone Binding Globulin (THBG).

2) Free form - It enters the body tissues where it is needed and this is the active form.

Hence, the T4 hormone can be measured as Free T4 or Total T4. The total T4 includes both bound and free forms circulating in the blood and can be affected by the amount of protein available in the blood to bind to them.

While the total T4 test is a useful indicator of T4 levels in the presence of normal binding proteins, it is not useful when levels of binding proteins are increased or decreased. For example, increased total T4 levels can be seen despite normal levels of free T4 levels and normal thyroid function due to an increase in thyroxine-binding proteins.

Thyroxine (T4) Total test is also done as a part of the Thyroid profile Total test which includes two more tests: Thyroid Stimulating Hormone (TSH) and Triiodothyronine (T3) Total.