TSH
Total and Free T4
Total and Free T3
Thyroid Binding Globulin (TBG)
Auto-antibodies (anti-TPO, anti-microsomal, anti-Tg)
Thyroid ultrasound
ECG - bradycardia, low voltage
VBG - hypercapnia from hypoventilation, possibly compensated if chronic
Hypothyroidism
Addison's disease
Congenital adrenal hyperplasia
Chronic fatigue syndrome
Levothyroxine toxicity
Constipation
Hyperthyroidism
Depression