A patient is said to have polyarteritis nodosa if he or she has 3 of the 10 following signs:

1. Weight loss ≥4 kg.
2. Livedo reticularis (a mottled purplish skin discoloration over the extremities or torso).
3. Testicular pain or tenderness. (occasionally, a site biopsied for diagnosis).
4. Muscle pain, weakness, or leg tenderness.
5. Nerve disease (either single or multiple).
6. Diastolic blood pressure greater than 90mmHg (high blood pressure).
7. Elevated kidney blood tests (BUN greater than 40 mg/dl or creatinine greater than 1.5 mg/dl).
8. Hepatitis B virus tests positive (for surface antigen or antibody).
9. Arteriogram (angiogram) showing the arteries that are dilated (aneurysms) or constricted by the blood vessel inflammation.
10. Biopsy of tissue showing the arteritis (typically inflamed arteries).