Depending on the tests ordered, these can included vitamin deficiencies, lyme disease, things that point toward lupus, etc. Unfortunately, there are no blood tests
that specifically point to multiple sclerosis
. MS diagnoses are made through a combination of ruling out other potential conditions, MRIs results, clinical exams, and sometimes lumbar punctures and evoked potentials. It can take time as there aren't any 'homerun' biomarkers for the disease, though they are working on finding them.