Hi,
As per the coding guidelines, "we need to assign codes from category 403, hypertensive chronic kidney disease, when conditions classfiable to 585-587 are present" and hence Unspecified renal failure code is 586, which comes under this guideline.
Also as per the tabular list, when we check into failure - renal - under hypertension it leads to 403.91, the same code for hypertension with chronic renal failure.
So we can the causal relationship applies to both chronic renal failure and unspecified renal failure as well. But not to renal failure- 584.9, as we know.
Hope this helps you and have a great day!
Thank You,
Purnima S, CPC