Triiodothyronine (T3) is one of the main hormones produced by the thyroid gland and helps regulate metabolism. T3 may be measured as part of thyroid function testing, although it is not routinely checked. It is typically assessed when thyroid dysfunction is suspected, especially in cases of hyperthyroidism, where T3 can be elevated even if T4 is normal. T3 results are interpreted alongside TSH and T4 to support diagnosis of thyroid disorders
Total Triiodothyronine (T3)
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Total Triiodothyronine (T3)
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Clinical Details
High Total T3
High T3 levels with low TSH suggest hyperthyroidism, A low TSH with high T3 or T4 usually indicates an overactive thyroid. This pattern may be seen in conditions such as Graves’ disease or thyroiditis, where excess thyroid hormone is produced.
Low Total T3
A low T3 level with high TSH may support a diagnosis of hypothyroidism, although T3 is not routinely used in assessing underactive thyroid, with T4 and TSH being the primary markers. Low T3 may also occur in nonthyroidal illness
Case Study
Delivering True Innovation
At Enfer Medical, we have integrated a cutting-edge and fully automated WASPLab® (Walk Away Specimen Processor) that has significantly enhanced our testing capabilities to ensure the highest of quality when processing patient samples.
Our Services
Service
Health & Wellness
General health and wellness testing can include a variety of tests, depending on the needs of the individual or recommendations of
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Service
Sexual Health
Regular STI screening facilitates early treatment and reduces the long-term consequences of infection.
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Respiratory Health
Rapid early pathogen identification has important treatment and infection control implications. See our range of tests here.
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Reproductive & Female Health
Hormonal analysis is hugely beneficial to identifying problems that can arise during the reproductive years.
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Sample Type &
Volume Required
Venous serum 5ml
Result Values
Quantitative results for T3 are reported in numeric value in ng/ml Please contact us for more information on the reference ranges used at Enfer Medical.
Patient
Request Form
For clients using the Enfer Medical Client Portal, the Enfer Medical Patient Request Form (PRF) will be generated when you have completed your “Test Request” within the portal linked below.
Please note that samples suspected of containing high risk pathogens such as Mycobacterium tuberculosis should be clearly identified on the form and packed separately from other samples.
24 hours
Results are available next working day.
7 Days a Week
This assay is available seven days a week.
Packaging
The packaging/preparation of samples for delivery to the laboratory are required to be in adherence to all national regulations for the safe transport of biological materials. HSE guidance can be reviewed HERE.
There are specific packaging instructions and labelling requirements requiring triple packaging including:
- Primary leak-proof container – tube or vial containing the sample.
- Secondary watertight container, with absorbent material, intended to protect the primary container.
- Outer container protects the secondary container.
- Patient Request forms must be placed between the secondary container and the outer shipping container.
Further information on the packaging/preparation of samples for delivery to the laboratory is contained within the Enfer Medical Laboratory User Manual which clients are provided with.
Storage & Stability
Specimens must be tested within 6 days of collection and stored at 2-8°C.
Transporting
Samples
Samples
In addition to the packaging of samples, the transport/delivery of clinical samples to the laboratory is required to be in adherence to all national regulations for the safe transport of biological materials. Enfer Medical provides a fully compliant logistics service, aligned with clients’ testing requirements.
Prompt transport of specimens:
To ensure prompt testing of samples and release of results within the published test turnaround times, samples should arrive to the laboratory by 18:00. Test turnaround time is measured from receipt of the sample at the laboratory until the time the authorised results are reported to users.
Acceptance/Rejection
of Samples
of Samples
In rare cases specimens may not be suitable for testing on arrival to the laboratory. In that case the sample will be rejected at the receipt stage and the service user will be notified immediately and an explanation as to why the sample could not be processed will be provided. Reasons why samples cannot be processed include but are not limited to:
- Samples received beyond the stability limits and/or not at the correct temperature indicated for each test.
- Incorrect sample type received.
- Leaking samples, sample not received or sample insufficient for analysis as stated below within sample requirements.
- Non-compliant samples or request forms i.e. those missing sample date information, missing sample test request and/or missing sample site/type information.
- Samples received without the necessary patient identifiers.
Clients will be provided with guidance on Sample Receipt Anomalies.
Our Services
Service
Health & Wellness
General health and wellness testing can include a variety of tests, depending on the needs of the individual or recommendations of
Find Out More
Service
Sexual Health
Regular STI screening facilitates early treatment and reduces the long-term consequences of infection.
Find Out More
Service
Respiratory Health
Rapid early pathogen identification has important treatment and infection control implications. See our range of tests here.
Find Out More
Service
Reproductive & Female Health
Hormonal analysis is hugely beneficial to identifying problems that can arise during the reproductive years.
Find Out More
Result Values:
Quantitative results for T3 are reported in numeric value in ng/ml Please contact us for more information on the reference ranges used at Enfer Medical.
Accessing
Your Results
Following receipt at the laboratory, results should be available on the next working day and will be reported to the referring clinician via the Enfer Medical Client Portal or in a format agreed with clients.
Established clients can login to the portal using the link above.