@kspowell Here is what Mayo Clinic has to say about vasculitis. There are several forms of vasculitis and the testing may be different for each.
https://www.mayoclinic.org/diseases-conditions/vasculitis/diagnosis-treatment/drc-20363485#:~:text=Blood%20tests.&text=Blood%20tests%20that%20look%20for,test%20%E2%80%94%20can%20help%20diagnose%20vasculitis.
Did someone suggest that you, or someone you know, might have vasculitis?

There are some 20 varieties of vasculitis (https://www.vasculitisfoundation.org/) all with their own complex symptoms. This is further complicated by doctors unfamiliar with the disease because, among other things, vasculitis is one of about 7000 rare diseases (https://rarediseases.org/wp-content/uploads/2019/01/RDD-FAQ-2019.pdf). When I was trying to find a doctor, the rheumatology group I ended up with took me in bec I had a primary marker: I was ANCA positive as documented by blood tests. If you have a host of symptoms your primary care physician might order some lab work try to determine which specialists to consult. Hope you find answers and medical help.