There are two situations in which there are black spots on a thousand footprints. The first is that the product itself is fake, which can usually be determined by identification. The second is that the wearer's toxin is relatively high, and Qianzuyin has the function of poison test, so the toxin in the body will react to the bracelet, but it should not be so fast; And if this bracelet is left for a long time, and then you wear it for a day, this situation is normal, and silver is extremely oxidized. If it turns black after oxidation, it can be brightened after long-term wear; You can wear it continuously for a long time to see if there are fewer and fewer black spots. If so, no problem. If not, it is recommended to determine whether it is a fake. If not, it is recommended to go to the hospital for a comprehensive physical examination, just in case.