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TSH (Thyroid Stimulating Hormone) Ultrasensitive

Also known as Thyrotropin, Thyrotropic hormone

You need to provide

Blood

This test is for

Male, Female

Test Preparation

Sample to be given at the same time of the day in follow-up cases.

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:

To measure the levels of TSH in the body.
As part of a thyroid profile total along with T3 and T4 tests.
To detect and monitor ongoing treatment of thyroid disorders (hypothyroidism or hyperthyroidism), like goiter, Grave’s disease, or Hashimoto’s disease.

To evaluate symptoms suggestive of an imbalance in thyroid hormone levels, such as fatigue, weight loss, hair loss, and changes to heart rate.

To detect an underactive thyroid gland in newborn babies.
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.

Answers to Patient Concerns & Frequently Asked Questions (FAQs) about TSH (Thyroid Stimulating Hormone) Ultrasensitive

Frequently Asked Questions about TSH (Thyroid Stimulating Hormone) Ultrasensitive

Q. Why is a TSH Ultrasensitive test performed?

Your doctor may suggest a TSH Ultrasensitive test if you have symptoms of hypothyroidism, like weight gain, fatigue, dry skin, hair thinning, slow heart rate, and depression, or hyperthyroidism, like weight loss, muscle weakness, anxiety, trouble sleeping, and frequent bowel movement.

Q. Is fasting required for a TSH Ultrasensitive test?

No, fasting is not needed before taking this test. However, your doctor will guide you if any special preparation is required.

Q. Is there any risk associated with an TSH Ultrasensitive test?

There is usually no risk associated with this test. However, some people may feel a slight sting while the needle is pricked and may experience some bleeding that is normal and usually not bothersome. Rarely some people may experience slight swelling or bruising at the site of the needle prick. Applying ice 3-4 times a day for about a week may help reduce swelling and bruising. If it does not get better, consult your doctor.

Q. Can I take a TSH Ultrasensitive test during pregnancy?

Yes, a TSH Ultrasensitive test along with other tests are usually recommended during pregnancy to measure the levels of thyroid hormones as thyroid disorders can complicate pregnancy.

Q. How can hyperthyroidism affect a pregnant woman and her baby?

An untreated hyperthyroidism during pregnancy can lead to miscarriage, premature birth, low birth weight of the baby, preeclampsia (a very high rise in blood pressure in late pregnancy), thyroid storm (a sudden, severe worsening of symptoms of hyperthyroidism), and congestive heart failure.

Q. What are the causes of high TSH in a newborn?

Congenital hypothyroidism is an important cause of elevated thyroid-stimulating hormone (TSH) in newborns. Other causes of an elevated TSH include transient hypothyroidism due to neonatal illness, premature birth, iodine excess, or deficiency. High TSH can also be seen in case the mother is taking some medicines that could affect thyroid hormone levels or the mother has some underlying thyroid disease.

Q. What is Hyperthyroidism?

Hyperthyroidism is a condition in which the thyroid gland is overactive and there is an increased production of thyroid hormones by the thyroid gland. Causes of Hyperthyroidism include Graves’ disease, multinodular goiter, thyroid nodules, toxic adenoma, inflammation of the thyroid, eating too much iodine, and too much synthetic thyroid hormone. Diagnosis of this condition can help to relieve the symptoms and prevent long-term complications.

Q. What are the symptoms of Hyperthyroidism?

Symptoms of Hyperthyroidism include: Rapid heartbeat (tachycardia) — commonly more than 100 beats/minute — irregular heartbeat (arrhythmia) or pounding of your heart (palpitations), sudden weight loss, nervousness, anxiety, irritability, tremor (usually a fine trembling in your hands and fingers), changes in menstrual patterns, increased sensitivity towards heat, changes in bowel patterns (especially more frequent bowel movements), an enlarged thyroid gland (goiter) which may appear as a swelling at the base of your neck, increased appetite, sweating, fatigue, muscle weakness, sleep disturbances, skin thinning, fine and brittle hair.

Q. What is Hypothyroidism?

Hypothyroidism, also called underactive thyroid or low thyroid is a condition in which the thyroid gland does not produce enough thyroid hormones. It can be commonly caused by intake of low iodine diet or Hashimoto's thyroiditis (an autoimmune disease). Less common causes include previous treatment with radioactive iodine, injury to the pituitary gland which secretes TSH, intake of certain medicines, previous thyroid surgery, or a lack of a functioning thyroid gland at birth.

Q. What are the symptoms of Hypothyroidism?

Hypothyroidism can cause symptoms such as tiredness (fatigue), hoarseness, constipation, feeling cold, dry skin, dry and thin hair, puffy face, weight gain, and muscle weakness. Along with that, one may experience decreased sweating, depression, slowed heart rate, increased blood cholesterol levels, pain, and stiffness in your joints, impaired memory, problems of infertility or menstrual changes, muscle stiffness, aches, and tenderness.

Q. What additional tests your doctor may ask for in case the TSH levels are not in the normal range?

If the TSH levels are not in the normal range, your doctor may ask for the following tests to establish the diagnosis of a suspected disease: T4 thyroid hormone test, T3 thyroid hormone test, Thyroid Hormone Binding Globulin (THBG) test, and Thyroid profile.

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