A pituitary hormone regulating the synthesis of thyroid hormones T3 and T4. It maintains normal metabolism, body temperature, energy levels, and cardiovascular and nervous system function. Elevated or reduced TSH levels can lead to weight gain, fatigue, swelling, and concentration issues.
Reference range: 0.4–4.0 mIU/L
Elevated levels may indicate:Hypothyroidism, autoimmune thyroiditis, pituitary tumors, certain medications (e.g., lithium, amiodarone)
Reduced levels may indicate:Thyrotoxicosis, excessive thyroxine intake, pituitary dysfunction