Thyroid stimulating hormone
(TSH)
Sample type :-
-
Serum (preferred)
-
Plasma (lithium heparin)
Uses:-
-
To diagnose an underactive or overactive thyroid gland.
-
To screen for thyroid disease before it causes symptoms, especially in newborns.
-
To evaluate a thyroid nodule, which is a lump on the thyroid gland.
-
To evaluate a goiter, which is enlargement of the thyroid gland.
-
To diagnose or rule out thyroid diseases, such as Hashimoto’s thyroiditis, Graves’ disease, and thyroid cancer.
-
To monitor a patient’s response to treatment for hypothyroidism, hyperthyroidism, or another thyroid condition.
-
Because thyroid disorders can complicate pregnancy, screening with a TSH test during pregnancy is recommended for some women
Precautions:-
-
If you are taking biotin or Vitamin B7 supplements, they should be discontinued at least 72 hours before the TSH test, as they can interfere with the accuracy of your test results.
-
If a red-top tube or plasma is used, transfer separated serum or plasma to a plastic transport tube.
-
Do not use oxalate ,EdTA or citrate plasma .
-
TSH testing in a newborn involves taking a few drops of blood from the baby’s heel.
Interfering factors :-
-
Have a history of miscarriage, premature birth, or infertility
-
TSH is not affected by variation in thyroid-binding proteins.
-
Iopanoic acid, ipodate, and an antiarrhythmic drug, amiodarone, cause changes in thyroid test results including increases in T4, free T4, and TSH and decreases of T3.
-
TSH may be affected by glucocorticoids, dopamine, and by severe illness.
-
Amiodarone may interfere with TSH.
Pre-analytical errors :-
- Citrate plasma ,improper labeling.
The corrective action
Reject the sample and another one are requested.
Post –analytical errors :-
- write wrong name on the report or wrong results and send the report to the wrong patient.
The corrective action
If the report is not delivered to the patient and this error is discovered, the correct name must be written, but if the report is delivered to the patient, you must communicate with him, apologise to him, and tell him that an error has occurred and replace it with the correct report.
Reference range :
0.4 to 4.0 mIU/L
Reference ranges will vary slightly depending upon the laboratory used for the test.