Renal Failure - What It Is.

Humans usually have two kidneys. These kidneys have many functions which include:

  • Removal of waste products from the blood
  • Removal of excess fluid. They do this by acting as a filter, thus producing urine.
  • Control of blood pressure
  • Control of the level of minerals in the bones
  • Production of red blood cells.

Renal failure is also known as kidney failure. It is a medical condition in which the kidneys fail to adequately filter waste products from the blood. Renal failure is mainly determined by a decrease in glomerular filtration rate, the rate at which blood is filtered in the glomeruli of the kidney. This is detected by a decrease in or absence of urine production or discovery of excess or increasing levels of waste products ((creatinine and urea) in the blood.

If the kidneys fail to filter waste products from the blood, the filtering must be done artificially and blood pressure may have to be controlled by medication. End stage Renal Failure (ESRF) or Established Renal Failure (ERF) is when kidney function is so bad that one is likely to die within weeks or months unless special treatment such as dialysis or transplantation is given.

Renal failure is mainly determined by a decrease in glomerular filtration rate, the rate at which blood is filtered in the glomeruli of the kidney. This is detected by a decrease in or absence of urine production or determination of waste products (creatinine or urea) in the blood. Depending on the cause, hematuria (blood loss in the urine) and proteinuria (protein loss in the urine) may be noted.

In renal failure, there may be problems with increased fluid in the body (leading to swelling), increased acid levels, raised levels of potassium, decreased levels of calcium, increased levels of phosphate, and in later stages anemia. Bone health may also be affected. Long-term kidney problems are associated with an increased risk of cardiovascular disease

There are two main forms of Renal failure:

1. Acute Kidney Injury

Acute Kidney Injury (AKI), previously called Acute Renal Failure (ARF) - This is often reversible with adequate treatment. It is a rapidly progressive loss of renal function, generally characterized by oliguria (decreased urine production, quantified as less than 400 mL per day in adults, less than 0.5 mL/kg/h in children or less than 1 mL/kg/h in infants); and fluid and electrolyte imbalance. AKI can result from a variety of causes, generally classified as prerenal, intrinsic, and postrenal. The underlying cause must be identified and treated to arrest the progress, and dialysis may be necessary to bridge the time gap required for treating these fundamental causes.

2. Chronic Kidney Disease

Chronic Kidney Disease (CKD) This is often not reversible. It can also develop slowly and, initially, show few symptoms. CKD can be the long term consequence of irreversible acute disease or part of a disease progression.


Symptoms vary from person to person. Someone in early stage of kidney disease may not feel sick or notice symptoms as they occur. Waste accumulates in the blood and the body when kidneys fail to filter properly, Accumulation of urea in excess amount is called Azotemia (when there are no symptoms) and Uraemia (when there are symptoms).

The following are the symptoms of kidney failure:

  • High levels of urea in the blood, resulting in:
    • Decreased or increased urinary volume
    • Less frequent urination, or in smaller amounts than usual, with dark coloured urine
    • Nausea
    • Vomiting
    • Increased frequency of nocturnal urination
    • More frequent urination, or in greater amounts than usual, with pale urine
    • Blood in the urine (hematuria)
  • High level of phosphates in the blood:
    • Shortness of breath
    • Anorexia
    • Fatigue
    • Nausea
    • Vomiting
    • Sleep disturbance
  • Excess fluid retention resulting in:
    • Swelling of the legs, ankles, feet, face and/or hands
    • Shortness of breath due to extra fluid on the lungs (may also be caused by anemia)
  • Pallor – due to reduced level of red blood cells (Anaemia). Anaemia occurs as a result of the inability of the diseased kidneys to produce the hormone called Erythroporetin. Erythroporetin stimulates the bone marrow to produce oxygen-carrying red blood cells. Other symptoms of Anaemia, apart from Pallor include:
    • Easy fatigability
    • Dizzy Spells
    • Shortness of breath
  • Other symptoms include:
    • Loss of appetite or sour taste
    • Difficulty sleeping
    • Darkening of the skin

Causes of Acute Kidney Injury

Acute kidney injury (previously known as acute renal failure) - or AKI - usually occurs when the blood supply to the kidneys is suddenly interrupted or when the kidneys become overloaded with toxins. Causes of acute kidney injury include:

  • Severe dehydration from excessive vomiting, diarrhea or blood loss
  • Sudden or sharp drop in blood pressure following severe burns injury, severe blood infection or surgery
  • Restricted or limited blood flow to the kidneys due to the narrowed kidney vessels
  • Primary or intrinsic kidney disease
  • Cancer of the kidneys, bladder or prostate.

Causes of Chronic Kidney Disease

The following are the causes of Chronic Kidney Disease (CKD):

  1. Long-term, uncontrolled hypertension
  2. Diabetes Mellitus
  3. Polycystic kidney disease is another well-known cause of CKD. The majority of people afflicted with polycystic kidney disease have a family history of the disease.
  4. Other genetic illnesses affect kidney function
  5. Overuse of common drugs such as aspirin, ibuprofen, and acetaminophen (paracetamol) can also cause chronic kidney damage

Treatments options for renal (kidney) failure

The following are the treatment options for renal failure:

  • Conservative method - This form of treatment involves drugs and a special diet. In the early stages of kidney failure, long before dialysis is required, conservative (medical) treatment is sufficient to keep one fit and well. Many people never need more than this.
  • Renal Replacement Treatment - This is applied when conservative treatment seems inadequate. There are two types:
    • Dialysis - This is the artificial process of eliminating waste (diffusion) and unwanted water (ultrafiltration) from the blood. In other words, dialysis is the artificial replacement for lost kidney function (renal replacement therapy). Dialysis may be used for patients who have become ill and have acute kidney failure (temporary loss of kidney function), or for fairly stable patients who have permanently lost kidney function (Chronic kidney disease)
    • Kidney transplant or renal transplant is the organ transplant of a kidney into a patient with end-stage renal disease.