Diabetes also affects the blood vessels and alters the flow of blood. Without adequate blood flow, it takes longer for a sore or cut to heal. Poor blood flow in the arms and legs is called "peripheral vascular disease." Peripheral vascular disease is a circulatory disorder that affects blood vessels away from the heart. If you have an infection that will not heal because of poor blood flow, you are at risk for developing ulcers or gangrene (the death of tissue due to a lack of blood).