Low cortisol state. Acute adrenal crisis is defined by the sudden drop in Hydrocortisone (or its equivalent) in the body, prompting acute physiological changes such as low blood sugar, lethargy, nausea, low blood pressure and sometimes even coma and death. Immediate steroid replacement is needed to reverse the above either via mouth (if the individual is stable and able to swallow) or via intra muscular/intravenous.
Adrenal crisis. An adrenal crisis or acute adrenal insufficiency is a potentially life-threatening condition that occurs when there is not enough cortisol produced by the adrenal glands. This can occur either from damage to the adrenal glands or the pituitary gland in the brain. The result can be weakness, hypotension, hypoglycemia, cardiovascular collapse, etc and can be fatal.