Hello, Your MIL aged 84 is suffering from end stage renal disease. She has history of hypertension. Yes, diet works wonders, it helps healing better and faster but can damage the organs (kidneys) in this case if taken wrongly. She should have been put into renal diet as soon as the diagnosis was made. If a person is suffering from kidney disease, some nutrients can build up and damage the kidney. A renal diet can help protect progression from kidney damage. In kidney disease there is need to control important nutrients like sodium, potassium and phosphorus, it needs to be monitored. Potassium built up in kidney disease patients may affect the heart beat as potassium is involved in how the muscles work. Taking renal diet is better. Kidney patients need to avoid certain fruits and vegetables and limit the amount of others. Phosphorus is another mineral that can build up in the blood when kidneys don’t function properly. It can trigger osteoporosis by pulling calcium from the bones. Certain cereals need be limited to one serving per week. You are suggested to consult the treating doctor and put her on renal diet. Do not loose hope, sometimes patients show good response when kept on diet control. It is good to know that you are a medical coder & have so much concern for your MIL. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician