T4 stands for
thyroxine
, one of two hormones your thyroid gland makes. The thyroid is a butterfly-shaped gland in your neck that helps control your body's growth and energy use. The T4 test measures the amount of T4 in your blood to show whether your thyroid works as well as it should.
Whats T4 means?
Thyroxine
, also known as T4, is a type of thyroid hormone. This test measures the level of T4 in your blood. Too much or too little T4 can indicate thyroid disease. The T4 hormone comes in two forms: Free T4, which enters the body tissues where it's needed.
What does a high T4 mean?
Abnormally high test results
Elevated T4 levels may indicate
hyperthyroidism
. They may also indicate other thyroid problems, such as thyroiditis or toxic multinodular goiter. Other reasons for abnormal results may include: high levels of protein in the blood. too much iodine.
What should your free T4 level be?
A typical normal range is
0.9 to 2.3 nanograms per deciliter (ng/dL)
, or 12 to 30 picomoles per liter (pmol/L). Normal value ranges may vary slightly among different laboratories. Some laboratories use different measurements or may test different specimens.
What does the T4 test show?
A T4 test
measures the blood level of the hormone T4, also known as thyroxine
, which is produced by the thyroid gland and helps control metabolism and growth. The T4 test is performed as part of an evaluation of thyroid function.
What is a bad T4 level?
Interpreting Results. In adults, the typical range for free T4 is between
.
9 and 2.4 nanograms per deciliter. Total T4 tends to vary more with age. An abnormally high T4 level may indicate hyperthyroidism, thyroiditis, or goiter.
What is a good T4 level?
Normal test range for an adult:
0.40 – 4.50 mIU/mL
(milli-international units per liter of blood). T4: thyroxine tests for hypothyroidism and hyperthyroidism, and used to monitor treatment of thyroid disorders. Low T4 is seen with hypothyroidism, whereas high T4 levels may indicate hyperthyroidism.
What happens if T4 is low?
Lower-than-normal T4 levels usually mean you have
hypothyroidism
. However, some people may have increased TSH levels while having normal T4 levels. This is called subclinical (mild) hypothyroidism. It is believed to be an early stage of hypothyroidism.
What is FT4 normal range?
FT4 normal values are
0.7 to 1.9ng/dL
. Individuals taking medications that modify thyroid hormone metabolism and those with a history of thyroid cancer or pituitary disease may be optimally managed with a different normal FT4 range. Total T4 and Total T3 levels measure bound and free thyroid hormone in the blood.
What happens when FT4 is high?
A level of free T
4
that is higher than normal could mean you have an
overactive thyroid
. Conditions associated with hyperthyroidism include Graves disease, an autoimmune disorder. Abnormally low free T
4
levels may signal hypothyroidism. This means your thyroid is not making enough hormones.
What is the difference between total T4 and free T4?
A Total T4
measures the bound and free hormone and can change when binding proteins differ
(see above). A Free T4 measures what is not bound and able to enter and affect the body tissues.
Is free T4 0.9 Low?
What your T4 Free test results mean? The normal values of free T4 range from 0.9 to 2.3 ng/dL. If your values are lower than 0.9; then,
it may be caused by hypothyroidism, severe acute illnesses, malnutrition
, fasting, or using some medications. If your results are above 2.3; then, it may be due to hyperthyroidism.
What does free T4 do in the body?
Because T4 is converted into another thyroid hormone called T3 (triiodothyronine), free T4 is the more important hormone to measure. Any changes show up in T4 first. T3 and T4 help to
control how your body stores and uses energy (metabolism)
. The thyroid hormones also help control many of your body's other processes.
Does low T4 cause weight gain?
According to Dr. Kitahara, if someone has low thyroid function, their TSH is high, and the thyroid hormones known as T3 and T4 are low—and
weight gain often occurs
.
Is a T4 level of 14 normal?
Normal levels in adults
In adults, normal levels of total T4 range from
5–12 micrograms per deciliter
(mcg/dl) of blood. Normal levels of free T4 range from 0.8–1.8 nanograms per deciliter (ng/dl) of blood. Normal T4 levels also vary across trimesters of pregnancy.
How do you treat low T4 levels?
The easiest and most effective treatment is simply
taking a thyroid hormone pill (levothyroxine) once a day
, preferably in the morning. This medication is a pure synthetic form of T4 which is made in a laboratory to be an exact replacement for the T4 that the human thyroid gland normally secretes.
