Chronic Kidney Disease
What is Chronic Kidney Disease?
Chronic kidney disease is the final common pathway in many different diseases that affect the kidney. Common causes include inflammations of the glomeruli (glomerulonephritis) and of the renal calices (pyelonephritis) as well as chronic high blood pressure (hypertension) and diabetes mellitus.
Chronic kidney disease is characterised by a progressive loss of renal function. Depending on the activity of the underlying disease process, renal function may be lost slowly or rapidly. The end stage of kidney failure may develop over many years or within only a few months.
In general, the functional units of the kidney – the nephrons – cannot recover after injury; i.e., they are either active or functionally dead. However, because there are so many nephrons, the kidneys have a large functional reserve. The body can cope with the loss of one kidney as well as a considerable accumulation of waste products.
Stages of chronic kidney disease
Defined by the level of the kidney function (glomerular filtration rate, GFR), there are five stages of chronic kidney disease (according to NKF-KDOQI Guidelines ). Stage 1 (GFR < 90 ml/min/1.73 m2) is the earliest, while stage 5 (GFR < 15 ml/min/1.73 m2) represents overt kidney failure. This stage is also called end-stage kidney disease (ESKD) or end-stage renal disease (ESRD). At this point, less than 15 % of the kidney tissue is working and dialysis is necessary for survival.
Can symptoms of Chronic Renal Failure be recognized easily？
The symptoms of kidney disease and chronic renal failure are not obvious during the early stage. They can include：
- Blood in urine / tea or dark color urine (hematuria)
- Frothy urine (albuminuria)
- Turbid urine (urinary infection)
- Pain on passing urine
- Difficulties in urination (not smooth in passing urine)
- Sand / stone in the urine
- Significant increase or decrease urine output, nocturia (have to pass urine frequently during the night)
- Loin / abdomen pain
- Swelling of ankles or eyelid, puffy face
When the kidney function deteriorates to the stage of severe renal failure (less than 25% of the normal function), there may be symptoms of uraemia:
- Frequent passing of urine at night, decreased urine output
- Loss of appetite, nausea, vomiting
- Fatigue, pale looking (anemia)
- Itchy skin
- Shortness of breath
- Edema (swelling ankle or eyelid)
- Drowsy, unconscious, convulsions, coma
Nutritional Management in Chronic Kidney Disease According to Disease Stages
When you suffer from chronic kidney disease, nutritional management is an essential part of your treatment plan. Depending on the severity of your disease, your recommended diet may change over time. Especially, in a more advanced stage of your disease when your glomerular filtration rate (GFR) continues to decrease, the amount of protein together with calories and other nutrients (e.g. minerals and vitamins) in your diet have to be adjusted to meet your changing needs.
Please note that the following nutrients should be carefully monitored if you suffer from chronic kidney disease:
- KDOQI Clinical Practice Guidelines for Chronic Kidney Disease: Evaluation, Classification and Stratification. Am J Kidney Dis 2002; 39 (Suppl 1): 1-222. http://www.kidney.org/professionals/KDOQI/guidelines_ckd/p4_class_g1.htm (last visited 30.03.2010)
- Fauci A, Braunwald E, Kasper DL et al.: Harrison´s Principles of Internal Medicine, 17th Edition, 2008