Aside from the discomfort, the habit could also cause serious health problems, from ulcers, infections - which could lead even to amputation of the foot or leg if the problems are left untreated.
When the researchers reviewed the footwear of 100 diabetics, they found that 63 of them were wearing shoes that did not fit. Usually, the shoe was too tight, and researchers believe they know why the tight-fitting shoe is being chosen by the diabetic.
With diabetes, the sufferer loses his or her nerve sensation in the toes and feet, and so the shoe has to be tight fitting in order to even feel that it's a good fit.
(Source: International Journal of Clinical Practice, 2007; 61: 1900-4).