The standard explanation of diabetic neuropathy takes about forty seconds. High blood sugar damages nerves. It starts in your feet. Check them daily. Keep your A1C down. All true, and all wildly incomplete. Neuropathy reaches into parts of life that rarely get mentioned at diagnosis — how steady you feel on stairs, whether you get lightheaded standing up, how your body responds to exercise, whether you can still tell when your blood sugar is dropping. People discover these one at a time, usually by being surprised by them.