Too much fat in the body that makes a person overweight can also lead to the development of hemorrhoids. Usually, obese people show excess fat buildup that is more concentrated in the abdominal area. This puts extra pressure on the pelvic and the rectal area. This can increase the strain on the veins running through the rectum and the pelvis, eventually causing hemorrhoids. If obesity and weight are not brought under control, the veins may continue to swell and inflate in size. Once these veins are stretched beyond a certain extent, it is unlikely that they will come back to their original size.