In inflammatory conditions, fibrinogen, other clotting proteins, and alpha globulin are positively charged, thus increases the ESR.[4] In non-inflammatory conditions, plasma albumin concentration, size, shape, and number of red blood cells, and the concentration of immunoglobulin can affect the ESR. Other non-inflammatory conditions that can also causes raised ESR are anemia, renal failure, obesity, ageing, and female sex.[2] Meanwhile, increased red blood cells (polycythemia) causes reduced ESR as blood viscosity increases. Hemoglobinopathy such as sickle-cell disease can have low ESR due to improper shapes of red blood cells that impairs stacking.