Table 1.

Causes of acute kidney injury (AKI).

Category of AKI	Mechanism	Causes
Pre-renal failure Renal hypoperfusion	Hypovolaemia/Hypotension	Haemorrhage, dehydration (diarrhoea and vomiting, heat), Osmotic diuresis (hyperglycaemia, iatrogenic), excessive diuretic use
	Redistributive shock	Sepsis, anaphylaxis, reduced plasma oncotic pressure in nephrotic syndrome, pancreatitis
	Poor cardiac function	Cardiogenic shock, severe sepsis,
	Renal vascular changes	Afferent arteriolar vasoconstriction (NSAIDs, ACE inhibitors, vasoconstrictors)
Intrinsic-renal failure Damage to the renal parenchyma	Glomerular damage	Primary or secondary glomerulonephritis (infective, autoimmune, inflammatory)
	Tubular damage	Ischaemia or nephrotoxins, sepsis
	Damage to the renal blood vessels	Haemolytic uraemic syndrome
	Interstitial damage	Nephrotoxins or infection, sepsis
Post-renal failure Damage to the renal outflow of urine	Obstruction within the upper renal tract	Stones or malignancy
	External obstruction of the upper renal tract	External compression due to a mass, constriction due to retroperitoneal fibrosis, Intra-abdominal compartment syndrome
	Obstruction to the lower renal tract	Bladder neck dysfunction, prostatic enlargement, uterine disease, obstructed catheters