Red blood cell count should be done if you experience symptoms like constant fatigue, shortness of breath, pale skin, joint pains, disturbed sleep etc. The sooner your issue is diagnosed, the better will be the treatment that you can avail. The red blood cells are cellular components of our blood that carry haemoglobin. Their main function is to carry oxygen from the lungs to the tissues and they also provide red colour to the blood. Red blood cell count is a test conducted to find out how many red blood cells are present in your blood. If there is deficiency or surplus of red blood cells in your blood, your tissues will be affected. This will result in your whole body getting affected adversely.