Adrenal fatigue occurs when your adrenal glands do not function at the proper levels. It is often triggered by prolonged, intense stress. However it may also arise as the result of an infection. Especially one that affects the respiratory system, like pneumonia, influenza or bronchitis. Adrenal fatigue causes symptoms that are similar to chronic fatigue syndrome; and is characterized by an overwhelming feeling of exhaustion that cannot be eased by rest or sleep. Often this is accompanied by a general feeling of malaise or un-wellness. Adrenal fatigue can also cause unwanted weight gain and high cortisol levels. While adrenal fatigue affects literally millions of people worldwide, it has yet to be recognized as a distinct syndrome by conventional medicine.