Arthritis patients often have questions about the blood tests their doctor orders. How important are blood tests in diagnosing arthritis? What blood tests are commonly ordered and what do they tell a rheumatologist about an individual patient? When a patient has negative blood test results for the arthritis indicators, but have all the clinical symptoms such as pain, redness, warmth, swelling, and stiffness in their joints - do the negative labs preclude a diagnosis of arthritis? Read more about blood tests for arthritis.