Hypertension is twice as common in diabetics as in non-diabetics. Blood vessel walls are pushed against by an elevated pressure of blood. The damage caused by excess sugar to the small blood vessels increases the risk of developing high blood pressure, in part because stiffening of the walls causes the pressure of the blood against the walls to increase. A blood vessel is like a rubber tube that carries blood from the heart to the rest of the body. It causes damage to the arteries when blood pressure is consistently high, which makes them less elastic and more susceptible to plaque buildup. Heart attacks are caused when these plaques become unstable and break off in the arteries of the heart. Having diabetes and hypertension both increases your risk of heart disease, and that risk is additive (meaning your risk is higher with both). In the United States, heart disease is the leading cause of death.