The existence of chronic kidney disease in an individual means his kidneys are not functioning normally for a longer period of time. Usually, kidney removes toxic residues in the blood. They also help maintain balance of fluids and salts(electrolytes) in the body. Residues and fluids in the body that are in excess are eliminated as urine. When the kidneys are damaged, the residues are gathering in the body and produce a malaise.
A chronic renal disease seems to appear suddenly, but in fact, it appears little by little, over many years. Each kidney has about one million small filters, called nephrons. When nephrons are damaged and no longer work, the remaining healthy nephrons take their position. If deterioration continues, increasingly more nephrons become inoperative and the kidneys are no longer able complete their functions.
It is possible to slow down kidney damage by medication and lifestyle change. For these to give best results, patient must work with his doctor and follow the therapeutic steps strictly.

Causes of chronic renal failure are not always known. But any disease or illness that damage blood vessels or other kidney structures can lead to  kidney failure. The most common causes of chronic kidney disease are:
- Diabetes mellitus. Diabetes causes about 35% of all chronic kidney disease. Increased levels of glucose (blood sugar) leads to alterations in renal blood vessels. If glucose levels remain elevated, kidney function is impaired progressively.
- High blood pressure. High blood pressure is due to other 30% of chronic kidney disease. Because blood pressure often increases in kidney disease, it can lead to progressive deterioration of renal function even if renal disease has another cause.
Other situations that can damage the kidney and cause chronic kidney disease include:
- Disease or kidney infections, as polycystic kidney, pyelonephritis (infection of the parenchyma and renal pelvis), glomerulonephritis (infection localized in the glomerular capillaries), or congenital kidney disease (born with that disease)
- Renal artery stenosis or obstruction. Renal artery leads blood to kidney.
- Other diseases as benign prostatic hyperplasia (an enlarged prostate), kidney stones or a tumor that prevents the discharge of urine from the kidney
- Chronic use of drugs that impair renal function as a side effect, eg pain medicines like acetaminophen (Tylenol) or ibuprofen or some antibiotics (gentamicin).
Diabetes and hypertension are the most common causes that lead to chronic kidney disease and eventually to chronic renal failure. Also, diabetes and hypertension may accelerate deterioration of renal function in people who have this disease with another etiology (cause).

Some of the causes that lead to chronic renal failure are related to age and genetic markers. Other factors that may increase the risk of chronic kidney disease can be controlled such as, for example, eating habits and exercise.
Risk factors that can not be controlled
The main risk factors that can cause chronic kidney disease are:
- Age - kidneys start to decrease in size since the age of 35 years. By the age of 80 years remains approximately 30% of functional renal mass
- Race - African-American and Caucasians are more prone to chronic kidney disease
- Gender - men have higher risk of developing chronic kidney disease than women.
- Family history - it is both a risk factor in developing diabetes and high blood pressure, two major causes of chronic kidney disease appearance. Polycystic kidney disease is one of the inherited kidney that can cause renal failure.

Risk factors that can be controlled

It is possible to slow progression of kidney disease, preventing or delaying renal failure by controlling the factors that increase the risk of damage to the kidneys such as:
- High blood pressure leading to gradual deterioration of renal capillaries
- Diabetes mellitus - increased glycemic can cause permanent kidney damage blood capillaries. Kidney damage progresses until the kidneys cease to function
- Consumption of protein and fat - A diet low in protein and fat helps your kidneys to function normally
- Certain drugs - should be avoided chronic consumption of drugs that alter renal function such as NSAIDs (Aspirin) or some antibiotics.