T4 serum, also known as thyroxine serum, is a blood test that measures the level of the thyroid hormone thyroxine (T4) in the bloodstream. Thyroxine is produced by the thyroid gland and plays a key role in regulating metabolism, growth, and development.
A T4 serum test is typically ordered as part of an evaluation of thyroid function, particularly in cases where a person is experiencing symptoms of hypothyroidism (underactive thyroid) or hyperthyroidism (overactive thyroid), such as fatigue, weight changes, and changes in heart rate.
Normal T4 serum levels can vary depending on a person’s age, sex, and other factors, but generally fall within the range of 5 to 12 micrograms per deciliter (mcg/dL). Low T4 serum levels may indicate hypothyroidism, while high T4 serum levels may indicate hyperthyroidism.
It is important to note that T4 serum levels can be affected by a variety of factors, including medications and other health conditions, and should be interpreted in the context of a person’s overall health and medical history. A healthcare provider can help to interpret T4 serum results and determine if further testing or treatment is necessary.
