My husband of 70 years old has had Parkinson s disease for 14 years and was diagnosed with Parkinson s Dementia 2 years ago but think he has had it much longer. He is now in Memory Care. His feet and calves are very swollen. They are giving him a water pill and potassium but still a big problem. He has no pain as his body no longer feels much. He has low blood pressure, good heart and lungs and has never had any swelling before. He is still able to walk. Can you tell me why he would have swelling? Thank You, Joy