Stress-related disorder is defined as an increased stress load or reduced ability to adapt that depletes the reserve capacity of individuals, increasing their vulnerability to health problems. Stress-related illness can encompass the previously mentioned conditions as the primary cause of dysfunction or as the result of the stress of the dysfunction. Excessive stress sometimes manifests as cardiovascular problems, including hypertension; digestive difficulties, including heartburn, ulcer, and bowel syndromes; respiratory illness and susceptibility to bacterial and viral illness; endocrine dysfunction, particularly adrenal or thyroid dysfunction and delayed or reduced cellular repair; sleep disorders; and breathing pattern disorders, just to mention a few conditions.