Diabetes is a metabolic disorder that affects many systems in the body. Nephropathy, retinopathy, peripheral neuropathy, and cardiac disease are major complications in the advanced stage of the disorder. Sub–cortical white matter hyperintensities (WMH), which are seen as multifocal and diffuse areas of hyperintensity on T2–weighted magnetic resonance imaging (MRI), are strongly associated with diabetes and some other conditions. We review the white matter changes and some peculiar neurological manifestations of uncontrolled blood sugar levels