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Chronic Kidney Disease

Last updated Feb. 27, 2018

Approved by: Krish Tangella MD, MBA, FCAP

Chronic Kidney Disease (CKD) is a gradual loss of kidney function, characterized by a decreased ability of the kidneys to remove waste and excess fluid from blood.

What are the other Names for this Condition? (Also known as/Synonyms)

  • Chronic Kidney Failure
  • Chronic Renal Disease
  • CKD (Chronic Kidney Disease)

What is Chronic Kidney Disease? (Definition/Background Information)

  • Chronic Kidney Disease (CKD) is a gradual loss of kidney function, characterized by a decreased ability of the kidneys to remove waste and excess fluid from blood
  • Nephrons are the functional unit of kidneys and comprise of glomeruli (blood vessels) and associated tubules. Blood passes through these nephrons and filters wastes and excess fluid through the small pores present in the glomeruli. This filtrate is called glomerular filtrate
  • As this filtrate passes through the tubules, its concentration is altered by tubular cells and the final product is excreted as urine. In an individual with normal kidney function, the glomerular filtration rate (GFR) is 90-120ml/min/1.73m2
  • There are 5 stages of Chronic Kidney Disease as explained below:
    • Stage 1: Kidney damage with normal or increased GFR (>90 mL/min/1.73 m2)
    • Stage 2: Mild reduction in GFR (60-89 mL/min/1.73 m2)
    • Stage 3: Moderate reduction in GFR (30-59 mL/min/1.73 m2)
    • Stage 4: Severe reduction in GFR (15-29 mL/min/1.73 m2)
    • Stage 5: Kidney failure (GFR < 15 mL/min/1.73 m2 or dialysis)
  • The signs and symptoms of Chronic Kidney Disease may include nausea, vomiting, swelling of the body, fatigue, muscle twitches, and dryness of skin
  • Chronic Kidney Disease is slowly progressive and eventually leads to end-stage renal disease, which needs treatment either by dialysis or kidney transplant

Who gets Chronic Kidney Disease? (Age and Sex Distribution)

  • Chronic Kidney Disease is generally known to occur in about 11% of the total adult population. Elderly adults age 65 years and over are more at risk for CKD
  • But, the condition may affect individuals belonging to any age group (children too)
  • It is observed in both males and females
  • It is more prevalent in African-American, Hispanic American, Asian and Indian American populations

What are the Risk Factors for Chronic Kidney Disease? (Predisposing Factors)

Some risk factors associated with Chronic Kidney Disease are:

  • Uncontrolled blood pressure (hypertension)
  • Uncontrolled diabetes
  • Hyperlipidemia; increased amounts of lipids in blood
  • Excessive use of non-steroidal anti-inflammatory drugs (NSAIDs), which are pain-relieving medications
  • Bilateral or unilateral renal artery stenosis (narrowing of the artery)
  • Benign prostrate hypertrophy; enlargement of the prostate gland in men
  • Various congenital syndromes affecting the kidneys

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Chronic Kidney Disease?

The following are some possible causes of Chronic Kidney Disease:

  • Diabetic kidney disease: Long-term uncontrolled diabetes leading to chronic kidney damage
  • Hypertension: Long-term uncontrolled hypertension leading to chronic kidney damage
  • Vascular diseases such as renal artery stenosis, clot formation in the kidney vessels, renal vein obstruction, and vasculitis (inflammation of blood vessels)
  • Glomerular disease (primary or secondary): There are different types of glomerular disease such as membranous nephropathy, focal segmental glomerulosclerosis, and membranoproliferative glomerulonephritis
  • Tubulointerstitial disease that is caused by drugs, infection, heavy metals, sarcoidosis, hypercalcemia, radiation, and polycystic kidney disease
  • Urinary tract obstruction that is caused by stones, stricture, benign prostate hypertrophy, and the presence of tumors

What are the Signs and Symptoms of Chronic Kidney Disease?

Individuals with stage 1 to stage 3 Chronic Kidney Disease are generally asymptomatic. The condition becomes symptomatic in stages 4 and 5, in which the GFR is typically less than 30ml/min/1.73 m2.

In such cases, the signs and symptoms may include:

  • Malnutrition; loss of body muscle
  • Muscle weakness
  • Peripheral edema - swelling of the limbs and face
  • Pulmonary edema - presence of fluid in the lungs, leading to breathing difficulties
  • Anemia, due to low red blood cell count
  • Fatigue; increased drowsiness/somnolence
  • Impaired immunity resulting in increased susceptibility to infections
  • Decline of cognitive function
  • Anorexia; loss of hunger
  • Nausea, vomiting, and diarrhea
  • Dry skin, severe itching (pruritus), skin discoloration and bruising (ecchymosis)
  • Failure to thrive
  • Erectile dysfunction and decreased libido
  • Abnormal absence of menstruation (amenorrhea)
  • Tendency to bleed

How is Chronic Kidney Disease Diagnosed?

The diagnosis of Chronic Kidney Disease may involve many of the following tests and studies:

  • Complete evaluation of medical history, along with a thorough physical examination
  • Laboratory studies such as:
    • Complete blood count (CBC)
    • Basic metabolic panel, which includes serum creatinine, urea, electrolytes and blood sugar evaluation
    • Urinalysis
    • Serum albumin levels: Patients may have low albumin due to urinary protein loss or malnutrition
    • Lipid profile: Patients with this disease are reported to have an increased risk of cardiovascular disease
  • Radiological tests including:
    • Renal ultrasonography: Renal ultrasound is important to look for fluid accumulation in the kidneys, or to detect the presence of a cyst or tumor
    • Computed tomography (CT) scan of the kidneys: It is a useful tool to define renal masses and cysts better, which are usually observed on ultrasonograms. It is also the most sensitive procedure for identifying renal stones
    • Magnetic resonance imaging (MRI) scan of the kidneys: It is a useful tool for patients who require a CT scan, but cannot receive an intravenous contrast
    • Renal radionuclide scan for renal artery stenosis 
  • Kidney biopsy: In this test, a small piece of kidney tissue is taken and sent to a laboratory for examination under microscope by a pathologist

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Chronic Kidney Disease?

The potential complications of Chronic Renal Disease include:

  • Hyperkalemia: Increased potassium level in blood can impair the heart’s ability to function properly; it can be a fatal condition
  • Pericarditis: Inflammation of the heart membranes causing severe chest pain
  • Personality changes, difficulty concentrating, seizures
  • Intractable volume overload or excess fluid in the body even after treatment, to reduce the same
  • Failure to thrive and malnutrition in children
  • Decreased sex drive or impotence
  • Weak bones with increased risk of fractures
  • Gastrointestinal symptoms such as nausea, vomiting, or loss of appetite 

How is Chronic Kidney Disease Treated?

For the treatment of Chronic Kidney Disease, the following 3 goals are generally aimed for:

  • Delaying progression of the disease
  • Treating the complications caused by the disease
  • Renal replacement therapy such as dialysis or renal transplant (as necessary)

Delaying the progression of Chronic Kidney Disease:

  • Controlling the systolic blood pressure (SBP) is very important. It is safe and best to maintain SBP levels below 130 mmHg
  • Glycemic control: HbA1C (glycated hemoglobin) level should be maintained below 7
  • Protein restriction: Protein restriction seems to retard the progression of Chronic Kidney Disease, if the pre-treatment albumin level is normal
  • Treatment of hyperlipidemia (high lipid or fat in blood)
  • Avoidance of painkillers including NSAIDS
  • Smoking cessation

Treating the pathologic conditions caused by Chronic Renal Disease:

  • Treatment of anemia when hemoglobin level is below 10 g/dL with erythropoiesis stimulating agents (ESAs)
  • Hyperphosphatemia, which is an electrolyte imbalance resulting in elevated levels of phosphate in blood, is generally treated with dietary phosphate binders (that prevent absorption of the element by the body) and dietary phosphate restriction
  • Hypocalcemia (a drop in calcium levels in blood) is treated with calcium supplements
  • Hyperparathyroidism (high levels of parathyroid hormone in blood, leading to loss of calcium and weakening of bones) is treated with calcitriol or vitamin D analogs
  • Excess fluid build-up (volume overload) is treated with loop diuretics, which prevent the re-absorption of water (and sodium) from the kidneys
  • Metabolic acidosis, which is excessive acid production by the body, is typically treated with oral alkali supplementation
  • Signs and symptoms due to increased blood urea nitrogen (BUN) and creatinine levels (known as uremic manifestations) are treated with long-term kidney replacement therapy that include hemodialysis, peritoneal dialysis, or kidney transplantation

How can Chronic Kidney Disease be Prevented?

  • Chronic Kidney Disease (CKD) due to certain causes such as high blood pressure, diabetes, excessive use of NSAIDS, and atherosclerosis may be prevented by proper treatment of the underlying disease/condition and with good treatment regimen and compliance
  • If the kidneys are affected due to causes that include vasculitis or glomerulonephritis, then it may not be preventable
  • In any condition, the progression of CKD can be delayed with early diagnosis and treatment of the underlying condition and suitable modification of lifestyle

What is the Prognosis of Chronic Kidney Disease? (Outcomes/Resolutions)

  • Chronic Kidney Disease generally progresses to end-stage renal disease (ESRD)
  • The rate of progression depends on the time of diagnosis, the use of preventive measures such as control of hypertension and diabetes, and timely initiation of renal replacement therapy

Additional and Relevant Useful Information for Chronic Kidney Disease:

Fluid accumulation in the body, known as volume overload, can affect the functioning of various organs in the body including the heart. When treatments to reduce fluid build-ups are unsuccessful, the condition is known as ‘intractable volume overload’.

What are some Useful Resources for Additional Information?

References and Information Sources used for the Article:

Helpful Peer-Reviewed Medical Articles:

Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: March 29, 2016
Last updated: Feb. 27, 2018