Abstract: The present invention is directed to methods for confirming that a multiple sclerosis (MS) patient is suffering from a relapse. In particular, methods comprising: comparing a concentration of one or more metabolite(s) present in a sample obtained from the patient with the concentration of the same one or more metabolite(s) in a reference standard, wherein the one or more metabolite(s) are selected from: leucine, lysine, asparagine, phenylalanine, glucose, ?-hydroxybutyrate, myo-inositol, a lipoprotein having a —CH3 group of an HDL and/or LDL, a lipoprotein having a —CH3 group of a VLDL, a lipoprotein having a —(CH2)n group of an HDL and/or LDL, a lipoprotein having a ?CH2 group, and an N-acetylated glycoprotein; and confirming or not that the patient is suffering from a relapse.