A patient has a blood disorder that causes a decrease in red blood cells. Which of the following symptoms could be an indicator of this disorder?
1) Exercise leads to lightheadedness because little oxygen is delivered to body cells.
2) Blood from a cut heals quickly because there is an increase in blood clotting.
3) A sore becomes infected because the blood cannot fight foreign pathogens.
4) Swelling occurs around a bruise because of an increase in white blood cells.