Chronic Kidney Disease: What Does it Mean for Me?
Chronic kidney disease (CKD) is a frightening term. The idea of a chronic disease attacking your vital organs is very unsettling, but CKD is actually very common. Around 3 million people in the UK are estimated to be suffering from it and many of these people will have no idea that there is a problem.
Most people have never heard of chronic kidney disease, and you would be right to wonder how something that sounds so serious, and is so common, can be so little known about. The answer really lies in the fact that, for many people, CKD will cause no symptoms and may well have no significant impact on their lives. It is, however, as important as it sounds.
Your kidneys are found around the back of your body, just above your waistline in the angle between your rib cage and your pelvis. They are about 10-12 cm in length and, as you might guess, they are the shape of a kidney bean. They carry out many important functions. Perhaps their most notable function is the removal of waste products from the blood and the production of urine, but they are also involved with the regulation of blood pressure, the maintenance of blood electrolyte levels, and the metabolism of vitamin D and calcium.
In its most serious form, CKD results in the kidneys stopping to function, sometimes described as kidney failure, and this causes waste products to build up in the blood which is eventually fatal if not treated with either dialysis or a kidney transplant. Thankfully, few people end up with kidney disease that is this severe, but even milder forms of CKD have important health implications.
What is Chronic Kidney Disease?
Many people associate the word ‘chronic’ with a severe problem but in medicine ‘chronic’ refers to something being persistent or long lasting. Most people’s chronic kidney disease is, in fact, mild. CKD is diagnosed when your kidney blood tests show reduced kidney function for a period of at least three months.
We measure kidney function with the eGFR blood test.
What does eGFR calculation mean?
Your eGFR is based on a calculation involving levels of the waste product creatinine in your blood, your age, your sex, and your ethnicity. Based on your eGFR we classify CKD into 5 stages.
An eGFR of above 90 is considered normal but can be classified as Stage 1 kidney disease if you have other markers of kidney disease such as protein or blood in your urine (which can be detected with a urine test).
Similarly, an eGFR between 60 and 90 is usually considered normal, but is classed as Stage 2 kidney disease if those same markers of kidney disease are present.
An eGFR persistently below 60 represents CKD regardless of any other sign of kidney disease.
Stage 3 CKD is an eGFR from 30 to 60, Stage 4 is an eGFR between 15 and 30 and Stage 5 is diagnosed with an eGFR below 15. It is at Stage 5 that treatments such as dialysis are usually considered.
The difficulty with CKD is that it causes very few symptoms in the early stages so many people are completely unaware of it. It is not usually until stages 4 or 5 that symptoms develop, and these include fatigue, nausea, itching, muscle cramps, and fluid retention.
What causes CKD?
There are many causes of CKD. Some of these are rare, such as autoimmune conditions or diseases that cause structural damage to the kidneys, and some are very common such as high blood pressure or diabetes. However, perhaps the commonest cause of all is ageing. About half of the population over the age of 75 have some degree of kidney disease, although this is usually mild and will progress very slowly, if at all.
If your eGFR is found to be low, this will normally lead to further investigations such as urine tests, an ultrasound of your kidneys and, possibly, a kidney biopsy.
How is CKD treated?
Most treatment for CKD is targeted at the underlying cause – essentially the aim is to avoid any further damage being done. This involves good management of blood pressure and diabetes, and the avoidance of medications (such as ibuprofen) that can harm the kidneys. There may also be specific treatment aimed at whatever disease is causing the problem, such as immunosuppressant medication for autoimmune conditions or an operation to relieve any physical obstruction to the urinary tract.
Most people are at little or no risk of becoming seriously ill or dying as a direct result of their kidney disease. However, CKD is a risk factor for cardiovascular disease, and it is this that is likely to cause problems for people with CKD. This means that people with CKD need to take extra care to look after their cardiovascular health which includes controlling blood pressure, controlling blood sugar levels, considering treatment to lower cholesterol and, of course, STOP SMOKING!
To make sure that the CKD is not progressing, your eGFR should be checked periodically. This might be done annually for mild kidney disease, but should be done much more regularly for those in the advanced stages of kidney disease.
Identifying CKD should not necessarily be a cause for panic. For most people it will be mild and will cause no symptoms. However, it is important to identify CKD to allow you to take extra steps to protect your kidneys, look after your cardiovascular health, and continue to live a long and healthy life.