The term »Sudeck« is usually heard in Slovene medical jargon to denote a rather frequent painful complication after surgery or injury, which was officially named the complex regional pain syndrome in 1994. There are quite a few hypotheses about its pathogenesis, and each of them contributes to the understanding of the syndrome. Recent studies have been based on the well-founded hypothesis about a metabolic disturbance, curable by restoring circulation by using the serotonin antagonist ketanserin, and metabolism using carnitine, the carrier of the acyl group of fatty acyl-CoA across the mitochondrial membrane. Diagnosis is primarily based on clinical signs and symptoms. The complication has remained a therapeutic challenge for various medical professions, including physical and rehabilitation medicine.