Welcome to HCM.
I can provide you guidance, though it may not be complete, as it requires physical examination and a battery of tests.
He needs to be evaluated and followed up by a nephrologist
, as is being done right now.
His diet needs to be adjusted - basically fluid restriction, moderate protein and salt restriction.
In addition he may need iron, calcium and B-complex supplements.
Depending on his progress, changes can be made on the diet as well as medicines.
If the fluid accumulation is excessive and blood potassium levels go up, the doctor may consider dialysis
. to remove the fluid and toxic chemicals causing the symptoms.
Kindly ensure he is under strict follow-up by the nephrologist to decide the right time for dialysis.
I have provided you the essence of management.
Hope this helps.