In Addison's disease, what level of cortisol is generally observed in the morning?

In Addison's disease, the adrenal glands are unable to produce sufficient amounts of cortisol, particularly in response to stress or during the early morning when cortisol levels are typically highest. Cortisol levels usually peak in the morning due to the diurnal rhythm of adrenal production, but in individuals with Addison's disease, this regulatory mechanism is disrupted. Consequently, morning cortisol levels are usually observed to be below 5 mcg/dL, indicating adrenal insufficiency. This low level is a significant marker for the diagnosis of Addison's disease, along with other clinical findings and laboratory tests. Therefore, the answer reflects the physiological changes that occur in Addison's disease, emphasizing the inadequate adrenal response to produce cortisol.