The T7 Index is the product of T4 x T3 Uptake, divided by 100. it is also known as the Free Thyroxine Index.
T7= (T4 x T3-Uptake)/100
This calculation is an attempt to correct for variations in thyroxine binding proteins.
Result interpretation:
Disorder | Total T4 | T3 Uptake | T7 |
Primary hypothyroid | Decreased | Decreased | Decreased |
Secondary hypothyroid | Decreased | Decreased | Decreased |
Hyperthyroid | Increased | Increased | Increased |
T3 Toxicosis | Normal | Normal | Normal |
Reference ranges:
T7 will usually be decreased in patients with hypothyroidism. It may also be low in patients with non-thyroid illness.
Understand and improve your laboratory results with our health dashboard.
Upload your lab reports and get interpretation today.
Our technology helps to understand, combine, track, organize, and act on your medical lab test results.
T7 will usually be elevated in patients with hyperthyroidism.
Interpret Your Lab Results
Upload your lab report and we’ll interpret and provide you with recomendations today.
Get StartedGet Started With Our Personal Plan
Advanced Plan
Unlimited Plan
Are You a Health Professional?
Get started with our professional plan
Welcome to Healthmatters Pro.
Save time on interpreting lab results with the largest database of biomarkers online. In-depth research on any test at your fingertips, all stored and tracked in one place. Learn more
Pro Plan
for health professionals
$45 per month
At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.
5-Methyltetrahydrofolate, Adiponectin, Albumin/Creatinine Ratio, Random Urine, Anti-Thyroglobulin ab. (0-39), C-Peptide, Serum, Ceruloplasmin, Cyclic AMP, Plasma, Dihydrotestosterone (female), Dihydrotestosterone (male), Estimated Average Glucose (eAG), Free Androgen Index, Free testosterone, Free Testosterone, Direct (Female), Free Testosterone, Direct (Male), Free Thyroxine, Free Thyroxine Index, Fructosamine, Glucose, Glutamic Acid Decarboxylase, Hemoglobin A1c (HbA1c), Homocysteine, Insulin (Fasting), Insulin Antibody, Insulin-Like Growth Factor I (IGF-1), Iodine, Serum/Plasma, 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 (0 - 1 IU/L), Thyroid Peroxidase Antibodies (Anti-TPO Ab), Thyroid Stim Immunoglobulin, Thyroid-Stimulating Hormone (TSH), Thyrotropin Receptor Ab, Serum, Thyroxine-binding globulin, TBG, TMAO (Trimethylamine N-oxide), Total T3, Tri iodothyronine (T3) Uptake, Triiodothyronine, Serum