Hi, welcome to our site. I am Dr Saumya Mittal. Read your query. That is a very significant question and i appreciate your problem. I will try my best to answer your query First and foremost, there is a definitive possibility that this may be diabetes.However, at 89, I am sure you have had sugars tested before, and they were obviously negative (else you would not be asking this query). so the chances are low though of course possible. Check sugars to be sure. However there are other possible causes that may explain this. 1. there may be a possibility of thyroid disorders- you may need thyroid function tests 2. deficiency of vitamins- suggest starting multivitamin tablets. there is no real harm in taking them. testing individual vitamin levels is an extensive and expensive proposition. just check hemoglobin though. Many other possibilities may affect the nerves which also simultaneously affect other parts of the bodies. I would there fore request you to submit a detailed query so I have details to think of and therefore I can help you better I hope this helps you. Inform the reports mentioned above so i can be of help further. Best of luck. I have given you the answer to the maximum considering the information provided. The results of the tests could further enhance my answer to you. Please do understand that some details could be extracted from a detailed history and examination. Looking forward to your return query with the details asked so that I can help you further. Please feel free to ask another query. Would be glad to help you. (If the answer has helped you, please indicate this)