Anemia is a condition caused by a lack of healthy red blood cells, or low hemoglobin, in the blood. Red blood cells contain hemoglobin, which is responsible for carrying oxygen throughout the body; when those levels are low, the decreased levels of oxygen can cause symptoms such as fatigue, dizziness, and headaches. There are many types of anemia, each with their own cause; iron-deficiency anemia is the most common.
A CBC (complete blood count) with Differential measures (among other things) the red blood cells in your blood and can be used to detect anemia. Iron, B-12, and folate are also measured since mineral and vitamin deficiencies are common causes of anemia.
Fast for 12 hours (no food or drink, except water).