Abstract
A laboratory study was performed comparing the patterns of urinary amino acid excretion in patients with chronic fatigue syndrome (CFS) with a control group of subjects without fatigue or allergy. Fifteen out of 21 patients in the CFS Group showed abnormal patterns with both reduced and increased excretion of some acids. In contrast, the control subjects showed only increased excretion of some acids, and a finding present in only four out of 20 subjects.