Renal insufficiency
Synonyms and keywords: Renal failure; azotemia; kidney failure; kidney insufficiency; renal disease; kidney injury; renal injury
For more detailed information please see the chapters on acute kidney injury and chronic kidney disease.  This page is simply an overview of these disease states.

# Overview
Renal insufficiency may broadly be divided into two categories: Acute kidney injury vs. chronic kidney disease:

# Definition of Terms

## Acute kidney injury (AKI)
Acute kidney injury (AKI), formerly known as acute renal failure, is characterized by an abrupt loss of kidney function resulting in a failure to excrete nitrogenous waste products (among others), and a disruption of fluid and electrolyte homeostasis. AKI is defined as any of the following:
- Increase in serum creatinine concentration by 0.3 mg/dL in 48 hours, OR
- Increase in serum creatinine concentration by more than 50% of baseline or 1.5 times baseline concentration within the past 7 days, OR
- Decrease in urine volume <0.5 mL/kg/h for 6 or more hours

## Chronic kidney disease (CKD)
Chronic kidney disease (or chronic renal insufficiency) is a broad spectrum of disorders that disturb the structural or functional integrity of the kidney for more than 3 months. CKD is defined as any of the following:
- Kidney damage for  3 months as defined by structural or functional abnormalities of the kidney, with or without decreased GFR, manifest by either pathological abnormalities or markers of kidney damage (including abnormalities in the composition of the blood or urine or imaging abnormalities), OR
- GFR <60 mL/min/1.73 m2 for 3 months with or without kidney damage

## Acute-on-chronic renal failure (AoCRF)
Acute-on-chronic renal failure (AoCRF) is defined as the presence of acute kidney injury on top of chronic renal disease. AKI of AoCRF may be reversible, and the aim of treatment is to return the patient to baseline renal function prior to the acute insult.

## Azotemia
Azotemia is neither a disease entity nor a clinical syndrome. It is a laboratory finding defined as an elevation in the concentration of nitrogenous waste products in the blood. Azotemia may suggest either kidney or non-kidney diseases. Azotemia is generally caused by:
- Increased synthesis of nitrogenous waste products: Liver injury or skeletal muscle injury
- Reduced loss of nitrogenous waste products: Acute or chronic kidney injuries
To view a comprehensive list of causes of azotemia, click here.

## Uremia
Uremia (urine constituents in blood) is a clinical syndrome caused by progressive accumulation of nitrogen waste products among patients with kidney failure who with unable to clear these waste products by the kidneys.
- Uremia is thought to account for the clinical features of chronic kidney failure that cannot be explained by other classical abnormalities of chronic kidney failure (abnormalities of ion concentrations or extracellular volume overload).
- Initially, uremia syndrome remains subclinical as eGFR ranges between 10 to 50% of normal GFR. However, when renal function worsens and GFR further declines (below 10 mL/min/1.73m2, manifestations of uremia become more prominent, signaling the need for renal replacement modalities (either dialysis or renal transplantation).
- Although experimental studies have validated the presence of uremia in the context of acute kidney injury (acute uremia), uremia is classically a feature of chronic kidney disease given the progressive nature of the waste product accumulation associated with the disease.

# Causes

## Causes by Organ System

## Causes in Alphabetical Order
- Cefadroxil
- Ceftazidime
- Cytarabine
- Cytomegalovirus immune globulin
- Desogestrel and Ethinyl Estradiol
- Dolutegravir
- Flurbiprofen
- Gadoxetate
- Hyperparathyroidism
- Hypoparathyroidism
- Ixabepilone
- Ibuprofen lysine
- Oprelvekin
- Oxaprozin
- Siltuximab
- Sorafenib