TSH

Description: A TSH test is a blood test that measures thyroid stimulating hormone levels in your blood’s serum and is used to screen for and monitor treatment of thyroid disorders such as hypothyroidism and hyperthyroidism.

Also Known As: Thyroid Stimulating Hormone Test, Thyrotropin Test, TSH test, Thyroid Test, TSH Screen Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

When is a TSH test ordered?

When a person has symptoms of hyperthyroidism or hypothyroidism, or an enlarged thyroid gland, a doctor may order a TSH test.

Hyperthyroidism can cause the following signs and symptoms:

• Heart rate has increased.

• Anxiety

• Loss of weight

• Sleeping problems

• Hand tremors.

• Weakness

• Diarrhea

• Visual disturbances, light sensitivity

• Puffiness around the eyes, dryness, discomfort, and, in some cases, bulging of the eyes are all possible side effects.

Hypothyroidism can cause the following signs and symptoms:

• gaining weight

• Skin that is dry

• Constipation

• Intolerance to the cold

• Skin that is puffy

• Hair loss is a common problem.

• Fatigue

• Women's menstrual irregularities

When a person is being treated for a thyroid disease, TSH may be ordered at regular intervals. The American Thyroid Association suggests waiting 6-8 weeks after changing a person's thyroid medication dose before testing their TSH level again.

In the United States, TSH screening is routinely performed on newborns shortly after birth as part of each state's newborn screening program.

What does a TSH blood test check for?

The pituitary gland, a small structure beneath the brain and beyond the sinus cavities, produces thyroid-stimulating hormone. TSH causes thyroxine and triiodothyronine to be released into the bloodstream by the thyroid gland. These thyroid hormones aid in the regulation of the body's energy usage. This test determines how much TSH is present in the blood.

The feedback mechanism that the body utilizes to maintain consistent quantities of thyroid hormones in the blood includes TSH and its regulatory hormone, thyrotropin releasing hormone, which comes from the hypothalamus. TSH synthesis by the pituitary gland increases as thyroid hormone concentrations fall. TSH stimulates the thyroid gland, a small butterfly-shaped gland that lays flat against the windpipe at the base of the throat, to produce and release T4 and T3. Thyroid production turns on and off to maintain generally steady levels of thyroid hormones in the blood when all three organs are operating regularly.

When the thyroid produces excessive amounts of T4 and T3, the affected person may have hyperthyroidism symptoms such as high heart rate, weight loss, agitation, hand tremors, itchy eyes, and difficulty sleeping. The most prevalent cause of hyperthyroidism is Graves disease. It is a chronic autoimmune condition in which the immune system creates antibodies that mimic TSH, causing the thyroid hormone to be produced in excessive levels. As a result, the pituitary gland may produce less TSH, resulting in a low blood level.

Weight gain, dry skin, constipation, cold intolerance, and weariness are all symptoms of hypothyroidism, a condition in which the thyroid produces fewer thyroid hormones. In the United States, Hashimoto thyroiditis is the most prevalent cause of hypothyroidism. It's an autoimmune disease in which the immune system attacks the thyroid, causing inflammation and destruction as well as the generation of autoantibodies. The thyroid generates low levels of thyroid hormone in Hashimoto thyroiditis. The pituitary gland may create more TSH, resulting in a high blood level.

TSH values, on the other hand, do not necessarily indicate or predict thyroid hormone levels. TSH is produced abnormally in some persons and does not work properly. Despite having normal or modestly increased TSH values, they frequently develop hypothyroidism. Thyroid hormone levels can be high or low in a variety of thyroid illnesses, regardless of the amount of TSH in the blood.

TSH levels may be elevated or lowered in rare cases due to pituitary dysfunction. In addition to pituitary dysfunction, an issue with the hypothalamus can cause hyperthyroidism or hypothyroidism.

Lab tests often ordered with a TSH test:

• T3 Free

• T3 Total

• T4 Free

• T4 Total

• T3 Reverse

• T3 Uptake

• Thyroid Peroxidase

• Thyroglobulin Antibodies

• Thyroid Panel

Conditions where a test TSH is recommended:

• Hyperthyroidism

• Hypothyroidism

• Hashimotos

• Graves’ Disease

• Autoimmune Diseases

• Thyroid Cancer

Commonly Asked Questions:

How does my health care provider use a TSH test?

Thyroid function and/or symptoms of a thyroid problem, such as hyperthyroidism or hypothyroidism, are frequently assessed with the thyroid-stimulating hormone test.

The pituitary gland, a small structure beneath the brain and beyond the sinus cavities, produces TSH. It's a part of the body's feedback system that keeps the thyroid hormones thyroxine and triiodothyronine in check and helps regulate the pace at which the body burns calories.

TSH tests are typically ordered in conjunction with or before a free T4 test. A free T3 test and thyroid antibodies are two further thyroid tests that can be ordered. TSH, free T4, and free T3 are sometimes ordered as part of a thyroid panel.

TSH is used to:

• Diagnose a thyroid issue in a patient who is experiencing symptoms.

• Check newborns for an underactive thyroid.

• Monitor thyroid replacement therapy.

• Monitor treatment of hyperthyroidism that involves medication.

• Assist women in diagnosing and monitoring infertility issues.

• Assist in determining the pituitary gland's function

• Screen adults for thyroid issues and diseases.

What does my TSH blood test result mean?

A high TSH level could indicate that:

• The person being examined has an underactive thyroid gland that isn't responding well to TSH stimulation owing to acute or chronic thyroid dysfunction.

• If a person has hypothyroidism or has had their thyroid gland removed, the dose of thyroid hormone replacement medicine may need to be changed.

• A patient with hyperthyroidism is taking too much anti-thyroid medication, and the dosage needs to be reduced.

• There is a problem with the pituitary gland, such as a tumor that causes TSH levels to be out of control.

A low TSH level could imply the following:

• An overactive thyroid gland

• Thyroid hormone prescription taken in excess by patients being treated for an underactive thyroid gland.

• Inadequate medication in an individual being treated for hyperthyroidism; nevertheless, after successful anti-thyroid treatment, TSH production may take a time to recover. This is why the American Thyroid Association recommends testing for thyroid hormones as well as TSH levels throughout treatment.

• The pituitary gland has been damaged, preventing it from releasing enough TSH.

An abnormal TSH result, whether high or low, suggests an excess or deficiency in the quantity of thyroid hormone available to the body, but does not pinpoint the cause for the abnormal result. Additional testing is frequently performed after an abnormal TSH test result to determine the reason of the increase or decrease.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.