Description and Purposes: An Overview -- Neurological Manifestations -- Dysautonomy -- Cardiology Manifestations -- Syncope, Arrhythmia and Cardiac Devices -- Urological and Kidney manifestations -- Ophthalmological and Dermatological Manifestations -- Gastrointestinal Symptoms -- Hematological Associations -- Orthopedic Care -- Association of Neoplasms -- Diagnostic tools -- Genetics and Epigenetics -- Treatment -- Clinical Course: An Overview -- Neurological Manifestations -- Cardiology Manifestations -- Kidney manifestations -- Ophthalmological and Dermatological Manifestations -- Gastrointestinal Symptoms -- Diagnostic tools -- Genetics -- Treatment -- Pathology and Differential Diagnosis -- Clinical Research -- The Role of Nursing in Chronic Patient's Care -- Chronic Pain and Quality of Life.