Chemotherapy may increase a person's risk of bruising easily, according to the American Cancer Society. This is because chemotherapy often destroys bone marrow cells, which are responsible for manufacturing the cells in a person's body that allow blood to clot, called platelets.
Destruction of bone marrow cells limits the amount of platelets as well as red and white blood cells in a person's body, states the American Cancer Society. The decrease in white blood cells may also lead to infection, as white blood cells are part of the body's immune system that is responsible for fighting off bacteria. The reduction in the number of red blood cells, which carry oxygen to body tissues, may result in anemia.