My husband is 74yo. Has had heart checked by cardiologist , passed stress test. Lungs checked by pulmonologist, that s also ok. Nephrologist says his kidneys are somewhat compromised, but not causing the symptoms he s having. His symptoms are dizziness off and on, extreme fatigue, no energy, pain in groin and down legs. Left foot starting to drag a little at times. No one seems to have a clue. Where should we go next?