Reference Value for Thyroid hormones
Thyroid
THYROXINE
(T4)
Increased levels are found in hyperthyroidism, acute
thyroiditis, and hepatitis. Low levels can be found in Cretinism,
hypothyroidism, cirrhosis, malnutrition, and chronic thyroiditis.
Normal Adult Range: 4 - 12 ng/dl
Optimal Adult Reading: 8 ng/dl
Optimal Adult Reading: 8 ng/dl
Free THYROXINE (T4)
A
low level may indicate a diseased thyroid gland or may indicate a non-functioning .
pituitary gland which is not stimulating the thyroid to produce
T4 . If T4 is low and
TSH is normal , that is more likely to indicate a problem with the pituitary .
TSH is normal , that is more likely to indicate a problem with the pituitary .
Normal Adult Range: 8-2 ng/dl
Free
Triiodothyronine (T3)
Sometimes the diseased thyroid
gland will start producing very high levels of T3 but still produce normal
level of T4. Therefore measurement of both hormones provides an even more
accurate evaluation of thyroid function.
Normal Adult Range1.4-4.4 pg/ml
THYROID-STIMULATING
HORMONE (TSH)
produced by the anterior pituitary gland
causes the release and distribution of stored thyroid hormones. When T4
and T3 are too high, TSH secretion decreases, when T4 and T3 are low, TSH
secretion increases. Mid range normal in most labs
is about 1.7. A high level of TSH combined with a low or normal T4 level
generally indicates hypothyroidism, which can have an effect on fertility.
Normal Adult Range:
.0.4-4.0 mlU/l