Chronic fatigue is a symptom, not a condition in its own right, and can have many causes. Those possible causes need careful investigation. Modern medicine relies heavily on the results of blood tests and has narrowed the ranges of these tests to exclude all but the clear-cut cases. This leaves many sufferers with 'normal' results but far from normal symptoms. In his latest book, naturopath Martin Budd brings together what the range of causes may be, how they can be investigated, and how individuals with chronic fatigue can be treated. With a greater understanding of what underlies chronic fatigue, many sufferers may find their way out of the downward spiral of unending exhaustion.