A healthy result should fall into the range 2.6 - 4 pmol/L.
Triiodothyronine or T3 is the most biologically active thyroid hormone in humans. The term “free T3” means the amount of T3 that is not bound to proteins in the blood. T3 acts on almost every cell in the body by setting the metabolic rate of the cell. T3 is also critical for growth and development, especially in fetuses and children. The thyroid gland produces and releases some of the T3 in the blood, but about 80% of T3 is produced from T4 or thyroxine in the liver, kidney, and thyroid tissue. Thyroid-stimulating hormone, also known as TSH or thyrotropin is produced in the pituitary gland an stimulates the release of T3 by the thyroid gland. Most clinical laboratories do not directly measure of free T3. Instead, they measure total T3 and thyroid hormone-binding index.
Normal Ranges for Free T3:
1-23 Months 3.3-5.2 pg/mL
2-12 Years 3.3-4.8 pg/mL
13-20 Years 3.0-4.7 pg/mL
>20 Years 2.3-4.2 pg/mL
Sources:
http://www.ncbi.nlm.nih.gov/books/NBK285568/
http://www.uptodate.com/contents/laboratory-assessment-of-thyroid-function
http://www.ncbi.nlm.nih.gov/pubmed/12625976
http://www.questdiagnostics.com/testcenter/BUOrderInfo.action?tc=34429&labCode=SJC
http://dx.doi.org/10.1001/jama.1990.03440110095035
http://www.uptodate.com/contents/thyroid-function-in-nonthyroidal-illness
http://www.ncbi.nlm.nih.gov/pubmed?term=7920008
http://www.ncbi.nlm.nih.gov/pubmed/6687730
http://www.uptodate.com/contents/overview-of-thyroid-disease-in-pregnancy
http://www.uptodate.com/contents/diagnosis-of-and-screening-for-hypothyroidism-in-nonpregnant-adults
https://www.uptodate.com/contents/diagnosis-of-hyperthyroidism
insert the value from you T3, Free test result.
Decreased free T3 levels in the serum usually indicate hypothyroidism or chronic or subacute thyroiditis. Drugs that interfere with the conversion of T4 to T3 will decrease free T3 levels, and increase T4 levels. In most cases, free T3 is a less useful indicator of thyroid function than free T4. Free T3 may be normal in hypothyroidism, when TSH levels are high and free T4 levels are low. Any serious illness can decrease free T3 levels. Abnormally low T3 may cause symptoms of hypothyroidism including weakness and fatigue, cold intolerance, shortness of breath, weight gain, constipation, cognitive problems, dry skin, hoarseness, and swelling (edema).
Some specific causes of low free T3 are:
- Hypothyroidism
- Chronic thyroiditis
- Subacute thyroiditis
- Serious, non-thyroidal illness
- Drugs:
Elevated free T3 levels may indicate hyperthyroidism, thyroid hormone resistance syndrome, or T3 toxicosis. Serum T3 levels can be expected to increase during normal pregnancy; however, hyperthyroidism should be suspected if free T3 levels exceed normal values for a pregnant woman in a given trimester. Free T3 is generally more accurate in cases of hyperthyroidism than it is for diagnosing hypothyroidism. Elevated T3 may cause symptoms of hyperthyroidism including excessive appetite, anxiety, heart palpitation, shortness of breath, sweating, weight loss, emotional disturbances, and intolerance to heat.
Some specific causes of high free T3 are:
- Hyperthyroidism (e.g. Grave’s disease)
- Acute thyroiditis (e.g. postpartum thyroiditis)
- Pregnancy (normal, unless it exceeds pregnancy normal values)
- T3 toxicosis
- Thyroid hormone resistance syndrome
$15 per month
Select this plan$59 per year
Select this plan$250 single payment
Select this planHealth is not exactly rocket science. You just have to know what your body needs and doesn't need. Your medical tests contain that information. Upload them to our service and we’ll help you understand organize, and act on them.
Get Started
"I was really concerned about my lab results and my GP was not able to see me for another week. Through HealthMatters I was able to interpret my results instantly."
"I've been keeping all my lab results in a spreadsheet, covering approximately 20 years. The HealthMatters team helped me upload that info into the cloud. I can show this data to my family and doctors now easily."
"I had no idea what my lab results meant. Here I found all the biomarkers that I was looking for online. Finally, I have not only organized them all neatly in one place, but I am also grateful to be able to understand what they mean."
At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put security measures in place to help protect against the loss, misuse or alteration of information under our control. We use procedural, physical and electronic security methods designed to prevent people who aren't authorized from getting access to this information. Our internal code of conduct adds additional privacy protection. See our Privacy Policy for more information.
Ceruloplasmin, Cyclic AMP, Plasma, Dihydrotestosterone (female), Dihydrotestosterone (male), Estimated Average Glucose (eAG), Free Androgen Index, Free testosterone, Free Testosterone, Direct (Female), Free Thyroxine, Free Thyroxine Index, Glucose, Glutamic Acid Decarboxylase, Hemoglobin A1c (HbA1c), Homocysteine, Insulin (Fasting), Insulin-Like Growth Factor I (IGF-1), Parathyroid Hormone (PTH), Serum, Pregnenolone, Reverse T3, Serum, Sex Hormone-Binding Globulin (SHBG), T3, Free, T4, Free, T4, Total (Thyroxine), T7 Index, Testosterone, Testosterone (Female/Child), Testosterone, Serum (Female), Thyroglobulin, Thyroglobulin Antibodies, Thyroid Peroxidase Antibodies (Anti-TPO Ab), Thyroid-Stimulating Hormone (TSH), Thyrotropin Receptor Ab, Serum, Thyroxine-binding globulin, TBG, Total T3, Tri iodothyronine (T3) Uptake, Triiodothyronine, Serum
