It determinates an inflamatory reaction of the renal pelvis
The renal chalices and principally the interstital tissue of the kidney
With lesion on the tubular system and glomerular lesions
The processes are shown on acute or chronic ways

In the acute cases, the therapy is simple and effective
But when the disease becomes chronic, it's proteiform and simulator
The diagnosis is stated only in advanced stages of the lesions
Such as chronic insuffienciy of the kidneys and maligant hypertension

In some cases the processes are diagnosed in the autopsy
The pyelonephritis constitute the most insidious of the renal affections
When it's chronic, it's responsiple for the majority of the death cases
By insuffienciy of the kidneys