Typically, a doctor may ask for overnight fasting or an empty stomach for a few hours before the test. Your doctor may also ask to avoid the use of some medicines before the test as those drugs may affect the results.
TSH test: Understanding the results
The normal TSH levels are 0.4 to 4.0 milli-international units per liter. If a person is being treated for a thyroid abnormality, the normal range is 0.5 to 3.0 milli-international units per liter.
If a person has a TSH value above a healthy range, it indicates his or her thyroid is underactive. This may indicate that he or she is suffering from hypothyroidism. When the thyroid gland is underactive, it produces fewer hormones, hence, the pituitary gland releases excess TSH to stimulate it.
If an individual has a TSH value below the normal range, it may indicate his or her thyroid is overactive, which usually occurs in hyperthyroidism. When the thyroid produces excess thyroid hormones, the pituitary glands release less thyroid stimulating hormones.
Depending on the thyroid stimulating hormone test results, a doctor can suggest medication, treatments, and other medical tests.
When should a THS test be repeated?
To confirm the thyroid gland disorder you may be asked to repeat the test. If you are undergoing treatment, your doctor may ask you to repeat TSH blood test after few months to check for the effectiveness of treatment. For newly diagnosed conditions or for severe conditions, the doctor may advise repeating the test at regular intervals to monitor disease progression and treatment.
TSH test Procedure
A thyroid stimulating hormone test is similar to other blood tests. Typically, a healthcare expert takes a sample of blood from a vein on the inside of the elbow.
The expert will first clean the skin of the selected area and tie an elastic band around the upper arm to draw blood easily. He or she will insert the needle and draw blood from a vein filled with blood.
Once the expert draws enough blood, he or she removes the needle and elastic band, cleans the area, and applies a bandage.
The expert, then, labels the blood sample and sends it to the laboratory for testing.