A Brief Overview Kidney Failure

Healthy kidneys clean your blood by removing excess fluid, minerals and wastes. They also make hormones that keep your bones strong and your blood healthy. But if the kidneys are damaged, they don't work properly. Harmful wastes can build up in your body. Your blood pressure may rise. Your body may retain excess fluid and not make enough red blood cells. This is called kidney failure.

Types of kidney failure

Renal failure can broadly be divided into two categories: acute kidney injury or chronic kidney disease. The type of renal failure is determined by the trend in the serumcreatinine.

Causes of kidney failure

Kidney failure can occur from an acute situation or from chronic problems.
In acute renal failure, kidney function is lost rapidly and can occur from a variety of insults to the body. The list of causes is often categorized based on where the injury has occurred.

Prerenal causes (pre=before + renal=kidney) causes are due to decreased blood supply to the kidney. Examples ofprerenal causes of kidney failure are:
hypovolemia (low blood volume) due to blood loss;

dehydration from loss of body fluid (for example, vomiting, diarrhea, sweating,fever);

poor intake of fluids;

medication, for example, diuretics ("water pills") may cause excessive water loss;

and abnormal blood flow to and from the kidney due to obstruction of the renal artery or vein.

Symptoms of kidney failure include:

High levels of urea in the blood, which can result in:

Vomiting and/or diarrhea, which may lead to dehydration

Nausea

Weight loss

Nocturnal urination

Foamy or bubbly urine

More frequent urination, or in greater amounts than usual, with pale urine

Less frequent urination, or in smaller amounts than usual, with dark coloured urine

Blood in the urine

Pressure, or difficulty urinating

A build up of phosphates in the blood that diseased kidneys cannot filter out may cause:

Itching

Bone damage

Muscle cramps (caused by low levels of calcium which can cause hypocalcaemia)

A build up of potassium in the blood that diseased kidneys cannot filter out (called hyperkalemia) may cause:

Abnormal heart rhythms

Muscle paralysis

Failure of kidneys to remove excess fluid may cause:

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)

Polycystic kidney disease, which causes large, fluid-filled cysts on the kidneys and sometimes the liver, can cause:

Pain in the back or side

Healthy kidneys produce the hormone erythropoietin which stimulates the bone marrow to make oxygen-carrying red blood cells. As the kidneys fail they produce less erythropoietin resulting in fewer red blood cells being produced to replace the natural breakdown of old red blood cells. As a result the blood carries less haemoglobin, which is known as anemia. This can result in:

Feeling tired and/or weak

Memory problems

Difficulty concentrating

Dizziness

Low blood pressure

Other symptoms include:

Appetite loss, a bad taste in the mouth

Difficulty sleeping

Darkening of the skin