(^368) Medical-Surgical Nursing Demystified
Before the test—Explain to the patient this is a non-fasting blood test. The patient
may be asked to stop taking certain medications, including birth control pills, for
up to 4 weeks before the test.
Parathyroid Hormone (PTH) Test
This test measures the level of PTH in the blood. It is used as a means of assess-
ing the level of blood calcium, since PTH is one of the major factors affecting cal-
cium metabolism. The test is performed to evaluate parathyroid function and to
check for abnormal calcium levels.Before the test—Explain to the patient to have nothing to eat or drink from mid-
night until after the test the next morning. Some prescripton drugs affect the PTH
test and the patient may be asked to stop taking them prior to the test.Prolactin Test
This test measures the level of prolactin in the blood. The test is done to determine
the cause of galactorrhea (inappropriate lactation), to diagnose infertility and erec-
tile dysfunction, and to assess for pituitary adenomas. Explain to the patient that
this is a non-fasting blood test.Triiodothyronine (T3) Test
This test measures the level of T3 in the blood in order to determine whether the
thyroid is functioning properly. It is used primarily to help diagnose hyperthy-
roidism and is usually ordered following an abnormal TSH or T4 test. Explain to
the patient that this is a non-fasting blood test.Thyroxine Total (T4) Test
This test measures the amount of T4 in the blood and is ordered to evaluate the
thyroid function and to help diagnose hyperthyroidism and hypothyroidism.
Explain to the patient that this is a non-fasting blood test.