One of the main problems that high blood glucose levels can lead to is damage to your nerves. This happens for two main reasons. Firstly, high blood glucose levels can directly cause damage to the nerves themselves. Secondly, they can cause damage to the small blood vessels that supply your nerves with the nutrients and oxygen they need. The nerves in your body that are most likely to be affected are the longest ones – those that have to reach to your feet and legs. If you have diabetes, nerve damage or poor blood supply is the likely cause of foot problems.