I am 30yr old, I am having pain n swelling in my left hand/wrist uptil elbow since 2 months (pain is since months & swelling since 10 days), did x-ray and NCV test but nothing came up in that, today I got blood test done (on 4th of my periods of 5day cycle) for ESR n Rf factor. ESR value are high 20 (normal range 0 to 12 mm/hr) and RF factor is within normal range 8.5 (normal range 0 to 12.5 IU/ml). Please suggest if higher range of ESR value is a matter of concern? Also getting this test done during 4th day of periods (of 5 day period cycle) will impact my test results value? What can be possible cause of concern for the pain?