Chronic Fatigue Syndrome (CFS) or Myalgic Encephalomyelitis (ME) has no clear aetiology, and is defined as severe and chronic fatigue that has lasted for more than six consecutive months, which is not due to physical exertion or other medical conditions associated with fatigue. CFS patients may suffer from four or more of the following symptoms: post-exertional malaise lasting for more than 24 hours; tender or swollen lymph nodes; recurring sore throat; unrefreshing sleep; significantly impaired short-term memory and/or concentration; headaches; or joint pain. Management practices have included rest, pharmacology, cognitive behavioural therapy and/or exercise therapy. This book discusses the internist's view on ME and complementary and alternative treatments. It also explores metal hypersensitivity as the cause of CFS; illness perception and management in CFS; exercise management practices; and innate immune changes in the peripheral blood of CFS patients.