MCH stands for Mean Corpuscular Hemoglobin, which is a calculation of the average amount of hemoglobin contained in each of a persons red blood cells. Hemoglobin is a protein in the blood that carries oxygen from the lungs to the cells through the bloodstream. The MCH blood test is done as a component of a blood test called a Complete Blood Count (CBC), which evaluates the composition of the blood, checking hematocrit, white blood cells (WBC), and platelets as well as hemoglobin and red blood cells (RBC) . MCH is not measured directly, but calculated based on the hemoglobin value (Hgb), which is the total measure of hemoglobin in the blood. Abnormally high or low levels of MCH, as determined by blood testing, can be an indication of a number of problems in the body, ranging from nutrient deficiencies to chronic diseases. If your MCH levels are abnormal, your doctor may be able to determine the cause with the help of other components of the CBC, such as MCV results, which measure the average size of red blood cells, or MCHC, which measures hemoglobin concentration. Blood tests to determine your nutritional status may also be done to determine whether nutritional deficiencies are an issue.