@maureen716 There are 2 ways to measure cobalt levels, and different values are considered "normal". One is a plasma test (lower readings), the other a serum test (higher value). What I do know is that with implants, anything below 7 is considered acceptable without evidence of a degrading device. I found an old record after I wrote earlier. At the time of my first revision surgery, my cobalt level was over 70, at the second it was 29. One year later it was 6.