Final answer:
If left untreated, total loss of adrenal cortical function can be fatal within 1 to 3 days.
Step-by-step explanation:
Total loss of adrenal cortical function is known as Addison's disease. If left untreated, it can be fatal within 1 to 3 days. Adrenal cortical function refers to the hormone production by the outer layer of the adrenal glands, specifically glucocorticoids and mineralocorticoids. Without these hormones, the body cannot properly respond to stress or maintain electrolyte balance, leading to severe complications and death.