thyroid function test updated presenatation

1. Thyroid Function Tests
Dr. F A Nizamuddin

2. Introduction to Thyroid Gland
• The thyroid gland is a butterfly-shaped organ
located in the front of the neck.
• It plays a crucial role in regulating
metabolism, growth, and development
through the production of thyroid hormones.

3. Thyroid Hormones
• Thyroxine (T4): The primary hormone
produced by the thyroid gland. It is converted
into T3 in various tissues.
• Triiodothyronine (T3): The active form of the
hormone, which is more potent than T4.
• Calcitonin: A hormone involved in calcium
homeostasis.

4. Importance of Thyroid Function Tests
• Thyroid function tests are essential for
diagnosing thyroid disorders, monitoring
treatment efficacy, and managing ongoing
thyroid conditions.
• Indications for testing include symptoms of
hypothyroidism (fatigue, weight gain) or
hyperthyroidism (weight loss, palpitations),
routine health check-ups, and follow-up of
known thyroid conditions.

5. Types of Thyroid Function Tests
• TSH (Thyroid-Stimulating Hormone): Measures the
level of TSH in the blood.
• Free T4 (Thyroxine): Measures the unbound T4
hormone in the blood.
• Free T3 (Triiodothyronine): Measures the unbound T3
hormone in the blood.
• Total T4 and Total T3: Measure both bound and
unbound hormones.
• Thyroid Antibodies: Detects antibodies that may
indicate autoimmune thyroid diseases.

6. TSH (Thyroid-Stimulating Hormone)
• Role: Stimulates the thyroid gland to produce
T4 and T3.
• Normal Range: 0.4-4.0 mU/L.
• High TSH: May indicate hypothyroidism.
• Low TSH: May indicate hyperthyroidism.

7. Free T4 (Thyroxine)
• Role: Primary hormone produced by the
thyroid gland, converted to T3 in tissues.
• Normal Range: 0.8-2.8 ng/dL.
• High Free T4: May indicate hyperthyroidism.
• Low Free T4: May indicate hypothyroidism.

8. Free T3 (Triiodothyronine)
• Role: Active form of thyroid hormone, more
potent than T4.
• Normal Range: 2.3-4.2 pg/mL.
• High Free T3: May indicate hyperthyroidism.
• Low Free T3: May indicate hypothyroidism.

9. Total T4 and Total T3
• Total T4: Measures both bound and unbound
T4.
• Total T3: Measures both bound and unbound
T3.
• When Used: Useful in specific clinical
situations where free hormone levels might be
misleading.

10. Thyroid Antibodies
• Types: Anti-TPO, Anti-Tg, and TSH receptor
antibodies.
• Significance: Presence of antibodies can
indicate autoimmune thyroid diseases such as
Hashimoto’s Thyroiditis or Graves’ Disease.
• Interpretation: Positive results suggest an
autoimmune component to thyroid
dysfunction.

11. Imaging Studies
• Ultrasound: Used to evaluate the structure of
the thyroid gland, detect nodules, and guide
biopsies.
• Radioactive Iodine Uptake: Assesses thyroid
function by measuring the uptake of iodine by
the thyroid gland.

12. Common Thyroid Disorders
• Hypothyroidism: Causes include autoimmune
disease (Hashimoto’s), iodine deficiency, and
certain medications.
• Hyperthyroidism: Causes include Graves’
Disease, toxic adenoma, and thyroiditis.
• Hashimoto’s Thyroiditis: Autoimmune disorder
leading to hypothyroidism.
• Graves’ Disease: Autoimmune disorder leading to
hyperthyroidism.

13. Case Studies
• Case 1: Patient with fatigue, weight gain, high
TSH, and low Free T4 indicating
hypothyroidism.
• Case 2: Patient with weight loss, palpitations,
low TSH, and high Free T4 indicating
hyperthyroidism.

14. Monitoring and Follow-up
• Regular monitoring of thyroid function tests is
essential in patients with thyroid disorders.
• Adjusting treatment based on test results to
ensure optimal thyroid function and symptom
control.

15. Conclusion
• Thyroid function tests are critical for
diagnosing and managing thyroid disorders.
• Regular monitoring helps in adjusting
treatment and ensuring patient well-being.

16. Thank You