When high blood glucose damages nerves throughout the body, the result is diabetic neuropathy. There are many theories about how high glucose impairs nerve function. One possibility: if high glucose levels damage the blood vessels that “feed” the nerves, disrupting blood flow to nerve cells, then the nerves themselves will become damaged.
That’s why people with diabetes are more prone to problems their feet and legs: The nerves in these areas become damaged, causing either loss of feeling in the feet or painful tingling and burning (peripheral neuropathy).
Both are dangerous, particularly the numbness. Even a small cut of blister (easy to overlook if you can’t feel it) can lead to an infection. Poor blood flow to the feet and legs can make the infection unstoppable. Your body is unable to supply enough immune system warriors and other factors to fight the infection and heal the wound. The result: Gangrene and the amputation of toes, a foot, or even a leg. Nerve damage isn’t limited to the legs and feet, but can also affect other areas of te body such as:
Damage to the nerves that lead to the penis and vagina can cause impotence and problems with arousal and orgasm.
Damage to the nerves that serve the heart can make the heart beat faster or at different speeds, possibly leading to a deadly condition called arrhythmia. It may also be the cause of “silent heart attacks” that kill heart muscle without a detectable twinge. This dangerous event can lead to unrecognized heart damage and heart failure.
Damage to the nerves that lead to the bladder can make it difficult to know when you need to urinate. Thus, you hold your urine in too long, resulting in bladder infections.
Ironically, damage to the automatic nervous system, which is responsible for all those involuntary reactions we have and movements we make, can make it difficult for people with diabetes to recognize when their blood sugar levels drop too low. This is a common occurrence, particularly among those who take insulin or other blood sugar medications.