Triiodothyronine (T3) Uptake
Other names: T3 Uptake, T-Uptake, T3 UPTAKE, T3 Uptake(T3U)
A T3 resin uptake (also called a T3 uptake or T3RU) is a blood test performed as part of an evaluation of thyroid function.
The T3 resin uptake is used by doctors to estimate the amount of TBG in the blood, and how much T4 and T3 in the blood is free form and available to affect the body.
The thyroid is a gland in the neck that produces the hormones that help regulate many body processes, including the following:
- growth,
- energy balance,
- body temperature,
- and heart rate.
Thyroid function involves the interaction of many hormones, including triiodothyronine (T3) and thyroxine (T4). Both of these hormones exist in two forms in the blood. The more abundant forms are bound to a carrier protein called thyroxin-binding globulin (TBG), which helps transport the hormones through the body. The less abundant forms circulate unattached or "free." Only the free forms of the thyroid hormones (free T4 and free T3) are available to affect body processes.
If there's either too much or too little TBG in the blood, the measurements of total T3 and T4 levels will be affected, which can make it difficult for doctors to tell whether a person actually has a thyroid problem without also knowing the results of the T3 resin uptake.
Some people have an inherited condition that involves high TBG levels despite normal thyroid function.
What does it mean if your Triiodothyronine (T3) Uptake result is too high?
High T3 uptake levels generally indicate a decrease in the levels of thyroxine-binding globulin (TBG) in the blood. This condition suggests that a larger proportion of the available thyroid hormones are free or unbound, as opposed to being attached to TBG. It's important to remember that T3 uptake is not a direct measure of the T3 hormone itself but rather reflects the binding capacity of the proteins in the blood that carry thyroid hormones.
High T3 uptake can be associated with several conditions, including:
- Lowered TBG Levels: This can be due to genetic factors, or it might be seen in conditions that reduce protein levels in general, such as nephrotic syndrome (a kidney disorder).
- Hyperthyroidism: In some cases, an overactive thyroid can lead to increased levels of free thyroid hormones, which can be reflected as high T3 uptake.
- Androgen Therapy: Taking androgens or anabolic steroids can lower TBG levels.
- Acute Illness: Some acute illnesses can temporarily alter TBG levels and thyroid hormone binding.
- Chronic Liver Disease: Certain liver conditions can lead to changes in the levels of TBG and other proteins.
As with low T3 uptake levels, high T3 uptake should be interpreted in the context of other thyroid function tests, such as T4 and TSH levels. The overall pattern of these test results helps to give a more accurate picture of thyroid function and can guide diagnosis and treatment decisions. It is essential to consult with healthcare professionals to understand these results properly and to determine the appropriate course of action.
All Your Lab Results.
One Simple Dashboard.
Import, Track, and Share Your Lab Results Easily
Import, Track, and Share Your Lab Results
Import lab results from multiple providers, track changes over time, customize your reference ranges, and get clear explanations for each result. Everything is stored securely, exportable in one organized file, and shareable with your doctor—or anyone you choose.
Cancel or upgrade anytime
What does it mean if your Triiodothyronine (T3) Uptake result is too low?
Low T3 uptake levels typically indicate an alteration in the binding proteins for thyroid hormones in the blood, rather than a direct change in the thyroid gland's function itself. It's important to understand that T3 uptake is not a direct measurement of the T3 hormone. Instead, it's a test that helps to estimate the amount of thyroxine-binding globulin (TBG) in the blood, a protein that carries thyroid hormones.
In general, low T3 uptake can be seen in conditions where the level of TBG is increased. This can occur in various situations, such as:
- Pregnancy: Hormonal changes during pregnancy can increase TBG levels.
- Estrogen Therapy: Taking estrogen, such as in birth control pills or hormone replacement therapy, can increase TBG levels.
- Liver Disease: Certain liver conditions can alter TBG levels.
- Genetic Factors: Some people naturally have higher levels of TBG.
- Acute Illness: Sometimes, severe illness can impact TBG levels.
However, interpreting T3 uptake levels requires considering them in conjunction with other thyroid function tests, like T4 and TSH levels. This comprehensive approach helps to accurately assess thyroid function and diagnose potential thyroid disorders. It's always recommended to consult with a healthcare professional for a precise diagnosis and understanding of test results.
Laboratories
Bring All Your Lab Results Together — In One Place
We accept reports from any lab, so you can easily collect and organize all your health information in one secure spot.
Pricing Table
Gather Your Lab History — and Finally Make Sense of It
Finally, Your Lab Results Organized and Clear
Personal plans
$79/ year
Advanced Plan
Access your lab reports, explanations, and tracking tools.
- Import lab results from any provider
- Track all results with visual tools
- Customize your reference ranges
- Export your full lab history anytime
- Share results securely with anyone
- Receive 5 reports entered for you
- Cancel or upgrade anytime
$250/ once
Unlimited Account
Pay once, access everything—no monthly fees, no limits.
- Import lab results from any provider
- Track all results with visual tools
- Customize your reference ranges
- Export your full lab history anytime
- Share results securely with anyone
- Receive 10 reports entered for you
- No subscriptions. No extra fees.
$45/ month
Pro Monthly
Designed for professionals managing their clients' lab reports
- Import lab results from any provider
- Track lab results for multiple clients
- Customize reference ranges per client
- Export lab histories and reports
- Begin with first report entered by us
- Cancel or upgrade anytime
About membership
What's included in a Healthmatters membership
Import Lab Results from Any Source
See Your Health Timeline
Understand What Your Results Mean
Visualize Your Results
Data Entry Service for Your Reports
Securely Share With Anyone You Trust
Let Your Lab Results Tell the Full Story
Once your results are in one place, see the bigger picture — track trends over time, compare data side by side, export your full history, and share securely with anyone you trust.
Bring all your results together to compare, track progress, export your history, and share securely.
What Healthmatters Members Are Saying
Frequently asked questions
Healthmatters is a personal health dashboard that helps you organize and understand your lab results. It collects and displays your medical test data from any lab in one secure, easy-to-use platform.
- Individuals who want to track and understand their health over time.
- Health professionals, such as doctors, nutritionists, and wellness coaches, need to manage and interpret lab data for their clients.
With a Healthmatters account, you can:
- Upload lab reports from any lab
- View your data in interactive graphs, tables, and timelines
- Track trends and monitor changes over time
- Customize your reference ranges
- Export and share your full lab history
- Access your results anytime, from any device
Professionals can also analyze client data more efficiently and save time managing lab reports.
Healthmatters.io personal account provides in-depth research on 10000+ biomarkers, including information and suggestions for test panels such as, but not limited to:
- The GI Effects® Comprehensive Stool Profile,
- GI-MAP,
- The NutrEval FMV®,
- The ION Profile,
- Amino Acids Profile,
- Dried Urine Test for Comprehensive Hormones (DUTCH),
- Organic Acids Test,
- Organix Comprehensive Profile,
- Toxic Metals,
- Complete Blood Count (CBC),
- Metabolic panel,
- Thyroid panel,
- Lipid Panel,
- Urinalysis,
- And many, many more.
You can combine all test reports inside your Healthmatters account and keep them in one place. It gives you an excellent overview of all your health data. Once you retest, you can add new results and compare them.
If you are still determining whether Healthmatters support your lab results, the rule is that if you can test it, you can upload it to Healthmatters.
We implement proven measures to keep your data safe.
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.