Triiodothyronine (T3) Test

The T3 Test at Pamel Laboratories measures the level of Triiodothyronine (T3), one of the key hormones produced by the thyroid gland. T3 plays a major role in regulating your body’s metabolism, heart rate, temperature, and energy levels. This test is especially useful in detecting hyperthyroidism (overactive thyroid) and monitoring thyroid hormone therapy.

T3 levels are typically checked alongside TSH and T4 for a comprehensive assessment of thyroid function.

What the Test Measures:

• The concentration of T3 hormone (Total or Free) in your blood

• Helps evaluate how well your thyroid is functioning

Purpose of the Test:

• Diagnose or monitor:

  • Hyperthyroidism (high T3)

  • Hypothyroidism (low T3, often with other thyroid markers)

• Investigate symptoms such as:

  • Unexplained weight loss

  • Rapid heartbeat

  • Nervousness or anxiety

  • Fatigue or cold intolerance

• Assess effectiveness of thyroid treatment or medication dosage

Sample Type: Blood sample (serum)
Fasting Required: No
Turnaround Time: 24–48 hours

Interpretation Guide:

• High T3 levels: May indicate hyperthyroidism, thyroid nodules, or thyroid hormone overdose

• Low T3 levels: May suggest hypothyroidism, severe illness, or pituitary gland problems

Should be interpreted in conjunction with TSH and T4 levels