What exactly is an adrenal crisis?

Life threatening. Your adrenal glands make hormones which help to maintain normal salt and sugar levels in your blood as well as normal blood pressure. An adrenal crisis is a severe presentation of adrenal insufficiency which is life threatening due to potential problems with severely low blood pressure, in addition to very abnormal salt and sugar levels.
Adrenal crisis. An adrenal crisis 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.