Presentation Symptoms/Physical Exam Hypothyroidism Hyperthyroidism Cold intolerance (↓ heat production) Heat intolerance (↑ heat production) Weight gain ↓ appetite Weight loss ↑ appetite Hypoactivity lLethargy Fatigue Weakness Hyperactivity Constipation Diarrhea ↓ reflexes ↑ reflexes Bradycardia Tachycardia, palpitations, arrhythmias Dry, cool skin Coarse, brittle hair Warm, moist skin Fine hair Diastolic hypertension (Na/H2O retention) Systolic hypertension Myxedema (facial/periorbital) Osteoporosis Heat intolerance (↑ heat production) Weight loss ↑ appetite Hyperactivity Diarrhea ↑ reflexes Tachycardia, palpitations, arrhythmias Warm, moist skin Fine hair Evaluation Labs Hypothyroidism Hyperthyroidism ↑ TSH (best first test) ↓ TSH (best first test) ↓ total T4 ↑ total T4 ↓ free T4 ↑ free T4 Hyper cholesterolemia (↓ LDL receptor synthesis) Hypo cholesterolemia (↑ LDL receptor synthesis) Elevated serum creatine kinase -- ↓ TSH (best first test) ↑ total T4 ↑ free T4 Treatment Treatment Hypothyroidism Hyperthyroidism Levothyroxine ThionamidesAblative131I therapy Ablative 131I therapy Thionamides Ablative 131I therapy