If you have osteomyelitis, could it show up in blood work?

No: The diagnosis of osteomyelitis is difficult. Unless there is a biopsy proven osteomyelitis the diagnosis most of the time is just an assumption base on x-rays and nuclear scans or ct or mri. Unless pt has septicemia( blood cultures positive) at same time other blood tests are nonspecificific ( esr, crp, cbc).

Not definitively: A very high sedimentation rate, e.g. Over 100, can increase suspicion for osteomyelitis, but is nonspecific & can go this high in a variety of other problems including vasculitis (inflammation of blood vessels) & some cancers.In fact, a high sed rate by itself in absence of any signs/symptoms/abnormal labs-studies is not helpful.Sed rate cannot prove osteomyelitis, only increase/decrease suspicion.

Yes: Bacteria can sometimes be isolated in blood cultures causing osteomyelitis. Also blood work can show increased white blood cells and increased inflammatory markers suggestive of infection.