Chronic kidney disease (CKD) is a progressive loss in kidney function over a period of months or years. Each of your kidneys has about a million tiny filters, called nephrons.
If nephrons are damaged, they stop working. For a while, healthy nephrons can take on the extra work. But if the damage continues, more and more nephrons shut down. After a certain point, the nephrons that are left cannot filter your blood well enough to keep you healthy.
When kidney function falls below a certain point, it is called kidney failure. Kidney failure affects your whole body, and can make you feel very ill. Untreated kidney failure can be life-threatening.
What you should not forget:
- Early chronic kidney disease has no signs or symptoms.
- Chronic kidney disease usually does not go away.
- Kidney disease can be treated. The earlier you know you have it, the better your chances of receiving effective treatment.
- Blood and urine tests are used to check for kidney disease.
- Kidney disease can progress to kidney failure.
Kidney Diseases are Common, Harmful and often Treatable
Common: Between 8 and 10% of the adult population have some form of kidney damage, and every year millions die prematurely of complications related to Chronic Kidney Diseases (CKD).
- The first consequence of undetected CKD is the risk of developing progressive loss of kidney function that can lead to kidney failure (also called end-stage renal disease, ESRD) which means regular dialysis treatment or a kidney transplant is needed to survive.
- The second consequence of CKD is that it increases the risk of premature death from associated cardiovascular disease (i.e. heart attacks and strokes). Individuals who appear to be healthy who are then found to have CKD have an increased risk of dying prematurely from cardiovascular disease regardless of whether they ever develop kidney failure.
Treatable: If CKD is detected early and managed appropriately, the deterioration in kidney function can be slowed or even stopped, and the risk of associated cardiovascular complications can be reduced.
How is kidney function measured?
The main indicator of kidney function is your blood level of creatinine, a waste product of the body produced by muscles and excreted by the kidneys. If kidney function is reduced, creatinine accumulates in the blood leading to an elevated level when a blood test is checked.
Kidney function is best measured by an indicator called GFR (Glomerular Filtration Rate) which can easily be estimated (eGFR), from measurement of the blood creatinine level, and taking into account, age, ethnicity and gender.
Stages of Chronic Kidney Disease (CKD)
Usually, kidney disease starts slowly and silently, and progresses over a number of years. Not everyone progresses from Stage 1 to Stage 5. Stage 5 is also known as End-Stage Renal Disease (ESRD).
Prevalence of CKD
About 1 in 10 people have some degree of CKD. It can develop at any age and various conditions can lead to CKD. It however becomes more common with increasing age. After the age of 40, kidney filtration begins to fall by approximately 1% per year. On top of the natural aging of the kidneys, many conditions which damage the kidneys are more common in older people including diabetes, high blood pressure and heart disease.
It is estimated that about one in five men and one in four women between the ages of 65 and 74, and half of people aged 75 or more have CKD. In short, the older you get the more likely you are to have some degree of kidney disease.
Causes of CKD
Diabetes Mellitus and High blood pressure (hypertension) are the most common causes of kidney disease. Diabetes has been established as the cause of around one-third of all cases and is the commonest cause of ESRD in most developed countries. The high blood pressure causes just over a quarter of all cases of kidney failure.
Other less common conditions include inflammation (glomerulonephritis) or infections (pyelonephritis). Sometimes CKD is inherited (such as polycystic disease) or the result of longstanding blockage to the urinary system (such as enlarged prostate or kidney stones).
Some drugs can cause CKD, especially some pain-killing drugs (analgesics) if taken over a long time. Often doctors cannot determine what caused the problem.
There is no cure for chronic kidney disease, although treatment can slow or halt the progression of the disease and can prevent other serious conditions developing.
The main treatments are a proper diet and medications, and for those who reach ESRD, long term dialysis treatment or kidney transplantation. In the early stages of kidney disease, a proper diet and medications may help to maintain the critical balances in the body that your kidneys would normally control. However, when you have kidney failure, wastes and fluids accumulate in your body and you need dialysis treatments to remove these wastes and excess fluid from your blood, dialysis can be done either by machine (hemodialysis) or by using fluid in your abdomen (peritoneal dialysis). In suitable patients a kidney transplant combined with medications and a healthy diet can restore normal kidney function.
A kidney transplant is an operation to place a healthy (donor) kidney in your body to perform the functions your own diseased kidneys can no longer perform.
Kidney transplantation is considered the best treatment for many people with severe CKD because quality of life and survival are often better than in people who use dialysis.
A kidney can come from a living relative, a living unrelated person, or from a person who has died (deceased or cadaver donor); only one kidney is required to survive. In general, organs from living donors function better and for longer periods of time than those from donors who are deceased.
Overall, transplant success rates are very good. Transplants from deceased donors have an 85 to 90% success rate for the first year. That means that after one year, 85 to 90 out of every 100 transplanted kidneys are still functioning. Live donor transplants have a 90 to 95% success rate. Long-term success is good for people of all ages.
Healthy kidneys clean blood and remove extra fluid in the form of urine. They also make substances that keep our body healthy. Dialysis replaces the blood cleaning functions when kidneys no longer work.
There are two types of dialysis: hemodialysis and peritoneal dialysis.
In hemodialysis, your blood is pumped through a dialysis machine to remove waste products and excess fluids. You are connected to the dialysis machine through a needle in a vein that is surgically enlarged (vascular access) or through a temporary plastic catheter placed in a vein. This allows blood to be removed from the body, circulate through the dialysis machine for cleansing, and then return to the body. Hemodialysis is generally done three times a week and takes between three and five hours per session.
Peritoneal dialysis is another form of dialysis used to remove waste products and excess water. It works on the same principle as hemodialysis, but your blood is cleaned while still inside your body rather than in a machine by adding clean fluid to your abdomen, letting it accumulate waste products from the blood and then draining it out. It is typically done at home. Some patients can perform peritoneal dialysis continuously while going about normal daily activities (continuous ambulatory peritoneal dialysis, CAPD)