A Complete Blood Count with ESR is a group of tests performed on a sample of your blood. These tests provide your doctor with information about your general health. The tests include white blood cell count (WBC), red blood cell count (RBC), hemoglobin (HGB), hematocrit (HCT), meancell volume (MCV), mean cell hemoglobin (MCH), mean cell hemoglobin concentration (MCHC) and platelet count.

This is the total number of white blood cells. WBCs are the most important cells found in the blood that fight infection. There are five types of WBCs.
Red blood cells carry oxygen to all parts of the body. A decrease in red blood cells may cause anemia, fatigue and shortness of breath.
Hemoglobin is a protein that helps the RBCscarry the oxygen.
The hematocrit is the packed red blood cell volume, measured in a percentage. It directly reflects the number of red blood cells present. A decreased hematocrit goes together with a decreased red blood cell count.
MCV, MCH, MCHC These three measurements together are called the red blood cell indices because they describe the size of the red blood cells, how much hemoglobin the cells contain and the percent of the hemoglobin concentration compared to the total volume of the cell. These are all helpful measurements when determining the cause of anemia.
An erythrocyte sedimentation rate (ESR) is a type of blood test that measures how quickly erythrocytes (red blood cells) settle at the bottom of a test tube that contains a blood sample. Normally, red blood cells settle relatively slowly. A faster-than-normal rate may indicate inflammation in the body. Inflammation is part of your immune response system. It can be a reaction to an infection or injury. Inflammation may also be a sign of a chronic disease, an immune disorder, or other medical condition.