In simple words: This is a two-hour blood test that checks how your body responds to a hormone called TRH. It involves taking four blood samples over two hours, one before you are given a dose of TRH and three afterwards. This test helps doctors understand how your thyroid is working.

This code represents a two-hour thyrotropin releasing hormone (TRH) stimulation panel. It includes measuring the thyroid stimulating hormone (TSH) levels in four blood samples: one baseline sample before TRH administration, and three samples taken after TRH administration, typically at 30-minute intervals for the first hour and then at the two-hour mark. This test assesses the pituitary gland's response to TRH stimulation and helps diagnose thyroid disorders, particularly hypothyroidism.

Example 1: A patient presents with symptoms of hypothyroidism, such as fatigue, weight gain, and cold intolerance. The physician orders an 80439 TRH stimulation test to evaluate the pituitary's response to TRH and help determine the cause of the hypothyroidism., A patient with a known pituitary disorder undergoes an 80439 TRH stimulation test to assess the gland's function and monitor the effectiveness of treatment., A patient with suspected central hypothyroidism undergoes the TRH stimulation test to distinguish between a pituitary or hypothalamic cause for the low thyroid hormone levels.

Documentation should include the patient's symptoms, the medical reason for ordering the TRH stimulation test, the time of TRH administration, the time of each blood draw, and the TSH levels in each sample. Any adverse reactions to TRH should also be noted.

** This test is time-sensitive, and accurate timing of blood draws is crucial for reliable results. Some payers may reimburse separately for specimen collection (e.g., 36415).