In Chronic Kidney Disease (CKD) there is an ongoing kidney injury that often progresses to more severe stages and the emergence of symptoms due to the loss of its critical functional role in a myriad of body processes. Although pre-existing kidney tissue injury in CKD is usually not reversible, it has long been known that the outcome of CKD is not necessarily all or none.
Stages of Chronic Kidney Disease
Symptoms suggesting CKD may be few to none in its early stages, only being discovered when hypertension, abnormal findings on routine urine testing, or swelling in the legs are discovered. With worsening kidney function, more serious symptoms may occur.
CKD frequently worsens over time. This is extremely important in the management of chronic kidney injury since arresting or modifying the time course and severity of the CKD would make an enormous impact on outcome expectations. The degree of kidney dysfunction is often grouped into five stages.
|CKD Stage||Remaining % of kidney function||Description|
|I||>90%||Normal overall kidney function|
|II||60-89%||Mild to moderate CKD|
|IV||15-29%||Moderate to severe|
** ESRD = End Stage Renal Disease also often called ESKD - End Stage Kidney Disease
Table 1. Guidelines for the staging of chronic kidney disease.
During progression through these stages the number of expected CKD symptoms increases although there is considerable variability. The staging of CKD provides your physicians with an overview of how fast your CKD injury advances and the types of signs and symptoms that should be evaluated.
|CKD Stage||Common signs and symptoms|
|I||Few to none|
|II||Note that some may have few to no symptoms|
- decreased appetite
|III||Any of the above +|
- sleep problems
- swelling of the feet
- urinating more or less than usual
- high blood pressure
- bone disease
|IV||Any of the above +|
- nausea and vomiting
- chest pain
- decreased mental sharpness
- muscle cramping or twitching
|V||- worsening of the above symptoms +|
- need for dialysis and/or a kidney transplant
Table 2. Typical symptoms associated with CKD according to the stage of the disease. Note that there is considerable overlap of symptoms between adjacent stages.
Complications of CKD as kidney function progressively declines include:
- the accumulation of metabolic waste products and potentially harmful drug levels,
- an impaired ability to properly sustain normal mineral and water balance in the body,
- the emergence of hypertension if not already present,
- anemia as the result of inadequate stimulation of red blood cells synthesis,
- the development of metabolic bone disease, with increased fracture risk and, in children, bone deformities,
- an increased risk of serious cardiovascular disease,
- the need for dialysis and/or kidney transplantation if the CKD progresses to Stage V.
Chronic Kidney Disease treatment
Scientific studies have identified factors that can hasten the overall deterioration of kidney function. A common thread between many of these is a stimulus to increase the workload on remaining healthy nephrons; this ultimately leads to further nephron injury in a self-defeating cycle.
Those treatments supported by proof or strongly suggestive evidence for slowing the rate of CKD progression include:
- Optimizing control of high blood pressure; hypertension is among the leading contributors to progressive CKD injury.
- Management of obesity which also is a contributor to the rate of progressive kidney injury in CKD.
- Smoking cessation: Smoking is associated with CKD. Compared to non-smokers, current smokers are about 60% more likely to develop CKD.
- Long-term control of blood sugar levels. Poorly controlled diabetes is a cause of CKD and CKD progression.
- Awareness of drugs that can cause immune or toxic injuries to the kidneys.
- Nutritional and lifestyle modifications that include reduction of the type and amount of dietary protein that can contribute to CKD progression. Dietary adjustments to help maintain water balance and normal levels of minerals such as sodium, potassium, calcium, and phosphates are essential.
- There are well-established treatments for many of the metabolic derangements and ongoing kidney injuries that are typical for CKD, in general. Several types of medications also have been shown to slow the rate of CKD progression. Two classes of blood pressure lowering (antihypertensive) medications (angiotensin-converting enzyme inhibitors and angiotensin receptor blockers) also have been shown to diminish the amount of protein in the urine (a common finding in CKD) while decreasing the functional demands on remaining nephrons. Recently, the FDA granted approval for the use of an SGLT2 inhibitor (dapagliflozin [Farxiga]) for CKD. SGLT2 inhibitors were initially developed as blood sugar-lowering agents in diabetics. However, further studies with dapagliflozin and several others have consistently shown both kidney and cardiovascular protective effects in both diabetics and nondiabetics with CKD. Along with their blood sugar lowering effects, it significantly slows renal functional decline.
CKD frequently worsens over time. The degree of kidney dysfunction is often grouped into five stages.
Although CKD cannot be cured, there are treatments that can slow its progression and minimize side effects and complications that affect lifestyle and health.
References and further reading
NIDDK/NIH What is chronic kidney disease?
The Kidneys – a Basic Guide. Kidney Research UK
Glomerulonephritis StatPearls, National Institutes of Health
Joyce, E., Ranganathan, S., Swiatecka-Urban, A. (2017). Tubulointerstitial Nephritis: Diagnosis, Treatment and Monitoring. Pediatr Nephrol 32(4):577-587.
Vesicoureteral Reflux (VUR) National Institute of Diabetes and Digestive and Kidney diseases, NIH.
Stages of Chronic Kidney Disease Healthline.com
Drug-induced renal disorders National Center for Biotechnology Information/NIH