Diapedesis is shown by:

Part of the swelling, due to injury or infection, is caused by diapedesis. The white cells are intensely active because apart from destroying bacteria they also work to form a barrier around an infection that can help prevent the rest of the body from becoming infected. In small localized infections, this effect provided by diapedesis can be quite effective. In larger infections, the migrating infection may overpower the migrating white cells.