|
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
T4, (Thyroxine)
Test CodeT4
Preferred Specimen
Serum, 0.1 mL minimum
Transport Container
SST tube
Transport Temperature
Specimen stable for 8 hours at room temp., 2 days refrigerated and >2 days frozen.
Reference Range
See report for normal ranges.
Clinical Significance
Secreted into circulation in response to the TSH. Elevated T4 levels are seen in hyperthyroidism and acute thyroiditis. Low levels of T4 are seen in hypothyroidism, myxedema, cretinism, chronic thyroiditis and sub-acute thyroiditis.