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A complete blood count (CBC) measures the size, number, and maturity of the different blood cells in a specific volume of blood. This is one of the most common tests performed.
Red blood cells are important for carrying oxygen and fighting anemia and fatigue. The hemoglobin portion of the CBC measures the oxygen carrying capacity of the red blood cells while the hematocrit measures the percentage of red blood cells in the blood.
White blood cells fight infection. Increased numbers of white blood cells, therefore, may indicate the presence of an infection. Decreased levels may indicate certain rheumatic diseases or reaction to medication.
Platelets prevent the body from bleeding and bruising easily. It is usually performed to check for a blood infection.