T4 ⬆️ but T3 ⬇️

The "Steroid Effect" on Thyroid Profiles!
You see a report: Low TSH + High T4.
Your reflex: "Hyperthyroidism! Start Methimazole!"
STOP! Look at the T3. 🛑
If T3 is Low, this picture doesn't fit Graves' or toxic adenoma (where T3 is usually high/normal).
The likely culprit? Systemic Steroids. 💊
Pathophysiology:
Central Effect: Glucocorticoids suppress TSH release from the pituitary.
Peripheral Effect: They inhibit 5'-deiodinase, blocking the conversion of T4 (inactive) to T3 (active).
Result: T4 accumulates (High), T3 drops (Low).
Management:
Do NOT start anti-thyroid drugs. This is a drug-induced physiological change, not a thyroid pathology. Re-evaluate TFTs after the steroids are tapered off.
Always treat the patient, not just the lab values! 🤝
#Endocrinology #ThyroidFunctionTests #Steroids #Pharmacology #DoctorsOfIndia #MedicalEducation #ClinicalPearls #IndianDoctors #GeneralPractice #MBBSLife

Видео T4 ⬆️ but T3 ⬇️ канала Clinical Guruji