First of all, about the causes of birthmarks. The birthmark is largely due to some behaviors of pregnant women. When the fetus is in the pregnant mother's belly, if the pregnant woman lacks some trace elements, it will lead to the lack of trace elements in the fetus, increase the accumulation of pigment, and may precipitate somewhere to form a birthmark. Irregular diet of pregnant women will also affect.
Secondly, birthmarks are not defects. Birthmark is not a disease, nor a defect, so there is no need to pay too much attention to it, nor does it have any meaning, let alone the reincarnation of human beings. Don't over-interpret, let alone exaggerate your imagination.
Finally, look at the birthmark with a calm mind. Be sure to treat birthmarks with a normal heart, because some people may have birthmarks on their bare skin, so don't laugh at them. This is a normal phenomenon. A birthmark is the same as no birthmark.
To sum up, this is the content of my popular science about birthmarks. Anyone who is interested has a look and get to know it. Don't be superstitious about it Birthmark is really not human reincarnation, but a natural phenomenon. Of course, this is my personal opinion. Without authority, everyone has a different opinion. As the saying goes, 1000 readers have 1000 hamlets.