ScienceDaily -- Red blood cells, which make up 45 percent of blood, normally take the shape of circular cushions with a dimple on either side. But they can sometimes deform into an asymmetrical slipper shape. A team of physicists have used simulations to explore how fluid flow might be responsible for this deformation, as well as how the deformation in turn affects blood flow. The insights could help understand the mechanisms involved in arterial disease and other blood flow-related ailments.