Description
Purpose of the Test:
• Assess the active thyroid hormone levels in the body
• Diagnose hypothyroidism (underactive thyroid) or hyperthyroidism (overactive thyroid)
• Monitor the effectiveness of thyroid hormone replacement therapy
• Help evaluate symptoms like weight changes, fatigue, mood swings, irregular heartbeat, or hair loss
• Provide a clearer picture of thyroid health, especially when total thyroid hormone levels are not conclusive
What the Test Involves:
• A blood sample is collected, usually from a vein in your arm
• The test specifically measures:
o Free T3 (Triiodothyronine): The active thyroid hormone that influences metabolism, energy, and organ function
o Free T4 (Thyroxine): The precursor hormone that is converted into T3 and regulates body metabolism and growth
• These tests provide a more accurate measure of thyroid function compared to total hormone tests, as they focus on the free, active forms of thyroid hormones
