TSH (Thyroid Stimulating Hormone) Ultrasensitive
Understanding TSH (Thyroid Stimulating Hormone) Ultrasensitive
What is TSH (Thyroid Stimulating Hormone) Ultrasensitive?
A TSH (Thyroid Stimulating Hormone) Ultrasensitive test helps measure the level of thyroid-stimulating hormone in the body. This test is used to assess thyroid function and to detect possible disorders of the thyroid gland. It is also performed in combination with T3 and T4 tests as part of thyroid profile testing.
Thyroid-stimulating hormone (TSH), also known as thyrotropin, is produced by the pituitary gland present in the brain. TSH stimulates the thyroid gland to release thyroid hormones triiodothyronine (T3) and thyroxine (T4). Together, TSH, T3 & T4 hormones play a vital role in controlling how your body uses and stores energy, and maintaining body weight and temperature.
A TSH (Thyroid Stimulating Hormone) Ultrasensitive test is highly accurate and can detect even small changes in the levels of TSH as this hormone is relatively stable with only little fluctuations throughout the day in healthy individuals. This test helps diagnose and monitor various thyroid disorders, such as goiter, Graves’ disease, or Hashimoto’s thyroiditis. These disorders are a result of either an overactive thyroid gland (hyperthyroidism) or an underactive thyroid gland (hypothyroidism). A TSH screening test is also recommended for women during pregnancy to check if they have adequate amounts of TSH, as this hormone is necessary for the healthy development of babies and to avoid pregnancy complications.
No special preparations are needed for a TSH test. However, do let your doctor know about all the medications you take as some of those can affect thyroid function. Biotin (Vitamin B7) is a commonly taken over-the-counter supplement that can lead to some aberrancy in your thyroid function test results even when the values are actually normal. Therefore, avoid taking biotin 2 days before this test.
Test result ranges are approximate and may differ slightly between different labs depending on the methodology and laboratory guidelines. Talk to your doctor about your specific test results. The test results will help them determine your medical condition and formulate an overall treatment plan. Also, narrate your complete medical history to help them correlate your clinical and laboratory findings.
What is TSH (Thyroid Stimulating Hormone) Ultrasensitive used for?
A TSH (Thyroid Stimulating Hormone) Ultrasensitive test can be done:
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To measure the levels of TSH in the body.
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As part of a thyroid profile total along with T3 and T4 tests.
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To detect and monitor ongoing treatment of thyroid disorders (hypothyroidism or hyperthyroidism), like goiter, Grave’s disease, or Hashimoto’s disease.
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To evaluate symptoms suggestive of an imbalance in thyroid hormone levels, such as fatigue, weight loss, hair loss, and changes to heart rate.
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To detect an underactive thyroid gland in newborn babies.
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To evaluate disorders like thyroid nodules and pituitary or hypothalamus gland disorders and monitor their treatments.
What does TSH (Thyroid Stimulating Hormone) Ultrasensitive measure?
A TSH (Thyroid Stimulating Hormone) Ultrasensitive test measures the levels of TSH hormone in the blood. TSH is produced by the pituitary gland located in the brain. Its function is to stimulate and regulate the functioning of the thyroid gland. It signals the thyroid gland to increase or decrease the production of thyroid hormones T3 and T4 (essential for regulating our body’s metabolism, temperature, heart rate, and growth) when their levels are low or high, respectively. Therefore, when the levels of T3 & T4 decrease, the pituitary gland is stimulated to release TSH. This high TSH level in turn stimulates the thyroid gland to release more thyroid hormones (T3 & T4); the vice-versa happens when the levels of thyroid hormones increase.
Interpreting TSH (Thyroid Stimulating Hormone) Ultrasensitive results
Interpretations
The TSH normal range may vary from lab to lab.
The TSH normal range for different age groups is given below:
Patients (Age) TSH Normal Range
Premature Infants (28-36 Weeks) |
|
1st Week of Life |
0.20-27.90 mIU/L |
Term Infants (>37 Weeks) |
|
Serum or Cord Blood |
1.00-39.00 mIU/L |
1-2 Days |
3.20-34.60 mIU/L |
3-4 Days |
0.70-15.40 mIU/L |
5 Days-4 Weeks |
1.70-9.10 mIU/L |
1-11 Months |
0.80-8.20 mIU/L |
1-19 Years |
0.50-4.30 mIU/L |
≥20 Years |
0.40-4.50 mIU/L |
Pregnancy |
|
First Trimester |
0.26-2.66 mIU/L |
Second Trimester |
0.55-2.73 mIU/L |
Third Trimester |
0.43-2.91 mIU/L |
- If your TSH level is increased, it usually indicates that you have hypothyroidism. Hashimoto’s thyroiditis is the most common cause of primary hypothyroidism.
- If your TSH level is decreased, it usually indicates hyperthyroidism. Graves' disease, multinodular goiter, and toxic nodules are some of the common causes of hyperthyroidism.
Note: TSH normal range levels show circadian variation (fluctuates during the 24-hour cycle), reaching peak levels between 2-4 am and at a low between 6-10 pm.