Test Description

The routine thyroid panel consists of: TSH (thyrotropin), T3 (triiodothyronine), T4 (thyroxine), free T3, and free T4. T3 along with T4 regulate how the body uses energy. Free T3 may be a more accurate assessment for thyroid function than T3, because it is not bound by proteins. Free T4 is usually ordered with T4 and other thyroid tests, but is not effected by protein levels which may be more accurate than T4 when screening for thyroid function.
TSH is used to screen for thyroid hypo- or hyperthyroidism. In areas of the world with sufficient dietary iodine, hypothyroidism is most commonly caused by the autoimmune disease Hashimoto’s thyroiditis (chronic autoimmune thyroiditis). Hashimoto’s may be associated with a goiter.

When should this test be ordered?
Symptoms of hyperthyroidism (Grave’s Disease) include nervousness, irritability, increased perspiration, heart racing, hand tremors, anxiety, difficulty sleeping, thinning of the skin, fine brittle hair, and muscular weakness. Symptoms of hypothyroidism include sluggishness, irritability, weakness, fatigue, sleepiness, weight gain or inability to lose weight, constipation, cramps and aches, course dry hair and skin.
High Risk · <= 1.9 (pg/mL) & >= 4.5 (pg/mL)
Your overall clinical presentation will help your medical provider determine if you have a thyroid condition.
Borderline Risk · None
None determined for these assays.
Low Risk · 2.0-4.4 (pg/mL)
Within Reference Range.
Testing Method Used
Electrochemilluminescence immunoassays.

Sample is stable for 7 days at 2-8°C.

Please ship samples daily.
Improvements and Prevention
Your medical provider may prescribe thyroid hormone supplementation if you have an underactive thyroid.
Specimen Type
Serum
Fasting Required
No, but may be done with other tests that requires fasting.
Drawing and Processing
  1. Draw from a vein into a SST tubetube1
  2. Invert tube (do not shake) 1-2 times to mix adequately
  3. Let stand upright in tube rack for 30 minutes
  4. Centrifuge for 15 minutes at 3300rpm
  5. Do not leave at room temperature for more than 1 hour
  6. Keep cold in a refrigerator to maintain stability, until ready to ship
Shipping Instructions
  1. Freeze ice packs 24 hours prior to use
  2. Place ice packs inside the Styrofoam insulated kit
  3. Place processed tubes inside biohazard bag, place inside kit
  4. Seal box, print airbill and adhere to box and wait for courier to pick up
Rejection Criteria
QNS; temperature out of range upon receipt; grossly hemolyzed or lipemic; wrong specimen type; sample stability exceeded for this analyte; unlabeled or mislabeled specimen.
References

1. Guber HA, Farag AF. Evaluation of endocrine function. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 24.

2. Salvatore D, Davies TF, Schlumberger MJ, et al. Thyroid physiology and diagnostic evaluation of patients with thyroid disorders. In: Melmed S, Polonsky KS, Larsen PR, et al., eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 11.
The information provided here is intended for educational purposes only and should not be used or substituted as medical advice. You should consult a healthcare practitioner regarding medical diagnosis or treatment.