Pam: The reason that other tests must be done is that ANA is very common in the normal population. Up to 20% of all normal women are positive for ANA, so a positive test requires additional testing. When a doctor sees a patient with unexplained pains, they will sometimes order an ANA as a screening test for systemic lupus, because almost all systemic lupus patients are positive for ANA using the newest testing methods. The followup tests are more specific autoantibodies to see if there are any specific antibodies for lupus, rheumatoid arthritis, Sjogren's syndrome, etc. Even patients with painful conditions like fibromyalgia have a higher chance of being ANA positive than the rest of the population.
Good luck, and I hope your doctors can help you.