Diabetes is a disease in which the body’s ability to produce or respond to the hormone insulin is impaired, resulting in abnormal metabolism of carbohydrates and elevated levels of glucose in the blood and urine.
Diabetes and poor control of blood sugar levels can eventually lead to nerve damage and thickening and hardening of the blood vessels. Nerve damage can decrease your ability to develop an erection and thickening and hardening of arteries can decrease the necessary blood flow. Both of these effects can negatively affect your ability to get and maintain an erection.