Cortisol is a glucocorticoid hormone produced in the glands atop the kidneys, called the adrenals. Cortisol's primary role is to maintain energy levels and body functions when confronted with emotional or physical stress. Specifically, cortisol helps regulate blood pressure, cardiovascular function, metabolism and elements of the immune system. The adrenal glands and pituitary gland can become overwhelmed by a variety of stressors and diseases, which cause low levels of cortisol and the corresponding negative effects.
Weakness and Fatigue
The primary effects from low levels of cortisol are diffuse weakness and fatigue, especially in the morning and mid-afternoon, according to a 2009 study conducted by M. Kumari and colleagues and published in the scientific journal "Pyschoneuroendocrinology." Cortisol is regulated by proper functioning of the pituitary gland, so any disruption in the pituitary has a "domino effect." Glucose and glycogen management, thyroid hormone production and the immune system are all disrupted and can lead to fatigue, headaches, sleep disruption and a reduced immune response when the pituitary and adrenal glands are not functioning well in tandem.
MayoClinic.com notes that the most common disease leading to low levels of cortisol is Addison's disease, a disorder of the adrenal glands. Tumors, infections, auto-immune response, trauma and drug toxicity of the adrenal glands or pituitary gland also lead to reduced production of cortisol.
Dehydration
Cortisol also regulates potassium and sodium levels within the body, so low levels can cause increased urination, dehydration, muscle weakness, muscle cramping and muscle pain, especially in the low back and legs.
Disrupted Metabolism
Cortisol is also involved in the body's metabolism of fats, proteins and carbohydrates, according to The Cortisol Connection. Abnormally low amounts of cortisol in the body disrupts metabolism, resulting in low blood sugar levels and reduced glycogen in the liver, which is used for providing quick energy. Much like the effects of diabetes, low levels of cortisol can initially cause brain-fog and lethargy, and progress to gastrointestinal symptoms, such as nausea, vomiting and diarrhea. Loss of appetite, weight loss and an inability to tolerate colder temperatures are also common symptoms.
Hypotension
Low levels of cortisol also cause a drop in blood pressure, leading to hypotension and reduced cardiac output. Low blood pressure can cause dizziness and lightheadedness, especially upon standing, and be dangerous for elderly people who have reduced balance. Extremely low levels of cortisol from chronic adrenal crisis can lead to collapse of the peripheral blood vessels and become a medical emergency.
Skin Discoloration
A discoloration of the skin, called hyperpigmentation, can also develop due to low cortisol levels. This occurs because cortisol stimulates other hormones that activate the melanocyte cells responsible for skin pigmentation. Merck Manuals notes that this hyperpigmentation is characterized by diffuse tanning of exposed portions of the body, with black freckles being prominent on the forehead, face, neck and shoulders.
References
- "Williams Textbook of Endocrinology -- 11th Edition"; H.M. Kronenberg et al; 2008
- "Psychoneuroendocrinology"; Cortisol Secretion and Fatigue: Associations in a Community Based Cohort; M. Kumari et al; November 2009
- MayoClinic.com: Addison's Disease and Cortisol
- The Cortisol Connection: Cortisol Effects
- Merck Manuals: Addison's Disease and Hyperpigmentation
