D-dimer is a very good screening test. If it is negative, it helps to rule out different processes, usually DVT (clots in the legs) or PE (clots that have broken off and traveled to the lungs). However, there are numerous things that can make it elevate. Depending on the cause of your neuropathy, it could be the cause of the elevated d-dimer. D-dimer values will typically rise with age, possibly secondary to various underlying chronic diseases.