Know Your Blood Parameter: Triiodothyronine (T3)

1. Parameter Name 

   Total T3 (Triiodothyronine)

   
   

2. Test Type 

   Blood

   
   

3. Normal Range 

   Adults: 80 – 200 ng/dL

   
   

4. High Levels Indicate 

   Hyperthyroidism, thyroiditis, Graves’ disease, or excess thyroid hormone intake.

   
   

5. Low Levels Indicate 

   Hypothyroidism, starvation, chronic illness, or pituitary dysfunction.

   
   

6. Why It's Tested 

   To evaluate thyroid function and diagnose hyperthyroidism or hypothyroidism.

   
   

7. Associated Symptoms (if abnormal) 

   High: Anxiety, palpitations, weight loss 

   Low: Fatigue, cold intolerance, weight gain

   
   

8. What To Do If Abnormal 

   Repeat test with TSH and T4; consult endocrinologist if values persist abnormal.

   
   

9. Common Conditions Related 

   Graves’ disease, Hashimoto’s thyroiditis, thyroid nodules

   
   

10. Nutrition or Lifestyle Connection 

    Iodine intake impacts thyroid health; avoid excess soy or goitrogens if hypothyroid.

    
    

11. References (APA Format)

    • MedlinePlus. (2023). T3 test.

    • Mayo Clinic. (2022). Thyroid function tests.

    • American Thyroid Association. (2023).