The test is also known as T4 or free thyroxine. Thyroxine-Free and a combination of triiodothyronine (T3) together produce thyroid gland. It is through T4 that the body control rate is measured. It is all regulated in a feedback system.
The doctor may order the T4 test if the doctor sees the abnormal result on a TSH test or suspects of hyperthyroidism or hypothyroidism. If the patient shows increased high rates, anxiety, sudden weight loss or being the insomnia, tremors in the hands or have visual disturbances, he can be a suspect for hyperthyroidism, and the T4 test can be called in for. Whereas weight gains, dry skin, cold intolerance, fatigue, hair loss, irregularity in menstruation cycle of women, constipation can be symptoms of hypothyroidism.
The test is painless and does not involve any complication. Venipuncture method is used to collect blood samples. The Thyroxine-Free remains unaffected by any medications. However, medicines components with estrogen that are mainly taken by women as birth control pills may hurt the report of the test. Doctors may often ask the patient to refrain from such pills before the test. It is recommended, that the doctor should be aware of the medicines taken by the patient.
The Thyroxine-Free test is used for the following reasons-
The health practitioner ties a belt around the arm to get the vein sight more significant and more precise. The blood to be drawn from the vein is cleaned with an alcohol pad A new needle is unwrapped in front of the patient. The needle is attached to a tube where the blood is collected by injecting the needle into the vein. The fist of the patient may be asked to close while drawing the blood.
After the blood is drawn from the arm, the belt is loosened, and blood is made to flow through the arm. For newborn babies and infants, the blood sample is drawn from pricking the heel of the baby. The collected sample is sent to the research laboratory for examination.
Type | Gender | Age-Group | Value |
---|---|---|---|
T4
|
UNISEX
|
all age group
|
4.6-12mcg/dl
|