T4 Total

The T4 Total Test is a blood test that measures the total amount of thyroxine (T4) hormone in the bloodstream, including both protein-bound and unbound T4.

Thyroxine is produced by the thyroid gland and plays an important role in regulating metabolism, energy production, growth, and body temperature.

This test helps healthcare professionals evaluate thyroid function and investigate possible thyroid disorders.

What Does This Test Check?

• Measures total thyroxine (T4) levels in the blood.

• Helps assess thyroid gland function.

• Supports the investigation of hypothyroidism (underactive thyroid).

• Helps evaluate suspected hyperthyroidism (overactive thyroid).

• May be used alongside TSH and T3 tests for thyroid assessment.

Sample Requirements

• Sample Type: Clotted Blood or Serum

• Required Quantity: 2–3 ml

• Department: Clinical Chemistry / Hormone Testing

Patient Preparation

• Fasting is generally not required unless instructed by your doctor or laboratory.

• Inform your healthcare provider about thyroid medications and supplements, especially biotin.

• Pregnancy, oral contraceptives, and certain medications may affect total T4 levels.

• Follow any specific sample collection instructions provided by the laboratory.

Important Information

Total T4 levels can be affected by changes in thyroid-binding proteins, even when actual thyroid function is normal. Results should be interpreted alongside TSH, Free T4, medical history, and clinical findings. An abnormal result alone does not establish a thyroid diagnosis.

Reporting Time: To be confirmed by the laboratory.

Please confirm test availability and sample collection requirements with the laboratory before booking.