Health and Hygiene — BIOLOGY STD 6 — Question

A bruise is an injury to the tissues under the skin where in small blood vessels break and blood oozes out in the injured part inside the skin only. It becomes bluish black in color. It may be caused by bumping into objects or by being hit or falling. They go away naturally within few days. Immediate use of cold pack reduces the coloration and swelling.
Whereas a blister is a small bubble like swelling of the skin filled with a watery substance. It may be caused by bums or allergies or diseases like chicken pox. Blisters should not be punctured. We should wash them with water and cover with clean bandage.