Aside from helping the body respond to stress, cortisol helps regulate glucose, metabolism and the immune system. Low cortisol levels can show outward signs that the body's adrenal secretion mechanisms are out of whack. Most symptoms tend to develop over the course of several months. According to the National Endocrine and Metabolic Diseases Information Service, the most common symptoms of low cortisol are chronic fatigue, weak muscles and hyperpigmentation.
Chronic Fatigue
Low cortisol production may be associated with Addison's disease, a condition in which the adrenal cortex that produces essential hormones for the body--including cortisol--is destroyed or compromised. Feeling tired or constantly sleepy is one of the most common symptoms. An article on Addison's disease by the Mayo Clinic reported that cortisol is one of the hormones responsible for helping to convert food into energy. Any interruption in hormone secretion can slow the body's metabolism, causing an increase in fatigue. According to the National Adrenal Disease Foundation, cortisol mobilizes nutrients, modifies the body's response to inflammation, stimulates the liver to raise the blood sugar, and also helps control the amount of water in the body. Loss of appetite and hypoglycemia, which are associated with lower cortisol secretion, can also cause malnourishment. This further exacerbates the feeling of fatigue.
Weak Muscles
Because low cortisol levels can dramatically reduce the body's ability to extract caloric energy from food, a lack of sufficient nutrients eventually causes muscles and related tissue to weaken. Muscles and joint tissue require adequate protein and calories to stay active and "alive." If these tissues aren't supplied with the appropriate nutrients, they tend to break down. This slows metabolism and the burning of calories. The Mayo Clinic reports that in addition to weak muscles, joint pain and weight loss can develop slowly--often over a period of several months.
Hyperpigmentation
The National Adrenal Disease Foundation says the adrenocorticotrophic hormone, or ACTH, helps regulate cortisol and its related functions. If there's too much ACTH and not enough cortisol in the body, a darkening of the skin may occur that may look like an unsuitable tan on an individual who feels very unwell. The National Endocrine and Metabolic Diseases Information Service says this darkening is most visible on scars; skin folds; pressure points such as the elbows, knees, knuckles and toes; lips; and mucous membranes such as the lining of the cheek. If people notice unexplained darkening in any or all of these areas, it's recommended they be tested for cortisol deficiency.
