With one in 10 Australians affected, kidney disease is surprisingly common, but a lack of awareness and understanding among the general population means it often goes undetected until it’s seriously advanced. Nephrologist Professor Karen Dwyer reveals the most common signs of kidney disease and shares advice on how to keep your kidneys as healthy. “Many people are living with kidney disease and yet are unaware,” says Professor Dwyer who is clinical director at Kidney Health Australia and professor of medicine and deputy head, School of Medicine at Deakin University. “While living with kidney disease can be challenging, early detection can slow progression significantly.”
Why is kidney health so important?
Our kidneys perform a number of vital functions including maintaining fluid, electrolyte and acid-base balance. Our kidneys are also important in removing ‘toxins’ from the body that build up in the course of living and with exposure to medications and other environmental agents. Furthermore, the kidneys secrete hormones that impact our bone health and blood count via making red blood cells.
What tests can I have to check kidney health?
Asking your GP for a kidney health check is a great way to start. It includes a blood test, a urine test and a blood pressure measurement. With these we are looking at what is your kidney function (via a blood test), do you leak protein from the kidney (via a urine test) and what is your blood pressure. Blood pressure and kidney disease are interconnected. High blood pressure can cause kidney disease and chronic kidney disease (CKD) can worsen blood pressure.
These tests should be done one to two yearly depending on the individual. For those with diabetes and high blood pressure, it’s recommended these are done yearly. In the presence of kidney disease, then check-ups are more frequent, with the rate depending on the level of kidney impairment. Checking your kidney health is quick and easy so be proactive in getting checked.
What does it feel like to have kidney disease?
As kidney disease progress, anaemia (low blood count) is very common and can lead to someone feeling tired, short of breath and unable to perform their usual activities. Having said that, the challenge with kidney disease is that there are not a lot of symptoms until very late: you can lose up to 90 per cent of kidney function before symptoms may be evident. Many people therefore will present very late in the progression of kidney disease.
How is kidney health connected to heart health?
The body is an integrated system and the various organs ‘talk’ to each other. With the heart and the kidneys, the function of one directly impacts the other. In the setting of heart disease, the kidneys are under a lot more strain and in the presence of kidney disease, heart disease is a significant burden and in fact is the most common cause of death amongst those living with kidney disease. Linking the heart and the kidney is diabetes which is highly prevalent and the most common cause of kidney failure. [By] addressing lifestyle and the advent of a raft of new medications the long-term outlook for kidney disease is improving. However to implement, you need to know. So get checked!”
What does the colour of urine and the frequency of urination tell us about kidney health?
Our kidneys are designed to regulate fluid balance so if there is too much fluid, then you pass urine and it will be clear. If you haven’t drunk enough, the kidneys conserve water and concentrate the urine and you will go less frequently and the urine will be darker in colour.
Thirst is the best indicator of if you need to drink fluid and there is no specific amount to drink. This is because each person is different and the amount of water you drink will be dependent on level of activity, body size, other health issues and medications. What urine should not be is red or dark brown, which may indicate blood, or cloudy, which may indicate an infection.
What is acute kidney injury (AKI)?
Acute kidney injury is when there is an insult or injury to the kidney that alters kidney function. This may be detected through a blood test where we see a change in kidney function and/or a reduction in urine output.
There are many causes of AKI. Some include a severe infection where your blood pressure drops or if there is a large loss of fluid and the amount of blood getting to the kidney is reduced. Sometimes there can be a problem within the kidney itself, an infection or inflammation, which can impact kidney function. Finally, obstruction to the kidney can result in AKI. This may be a kidney stone or other issues in the bladder that might obstruct the flow of urine out causing pressure to build up.
Whilst the kidney can heal after an AKI, it results in a scar. The more scars in the kidney, the more likely that CKD will occur. Once there is CKD there is less ‘healthy’ kidney and if there is another injury there is likely to be another episode of AKI. So there is a bidirectional relationship between AKI and CKD.
What are kidney stones?
Kidney stones are hard conglomerates [masses] that can form in the kidney. When they move into the ureter, the drainage pipes from the kidney [to the bladder] it can cause pain. The ureters are very small and the stones usually larger.
The most common stones are made of calcium phosphate or calcium oxalate; uric acid stones are less common. Causes of kidney stones include excess abdominal weight, diabetes, high blood pressure, metabolic syndrome, gout, gastric bypass surgery, Crohn’s disease, excess calcium and/or vitamin D supplementation, hyperparathyroidism, rare inherited conditions and very high protein intake.
What is chronic kidney disease (CKD)?
CKD is a reduction in kidney function and/or loss of protein from the kidney that persists for at least three months. The most common causes of CKD are diabetes and high blood pressure. Other causes include heart disease and excess weight. Being a smoker, episodes of AKI and a family history of kidney disease all increases susceptibility to CKD.
One in 10 Australians have CKD and significantly, the majority are unaware. In early stages of kidney disease, the impact on daily life is minimal. However as CKD progresses the impact becomes substantial with the development of symptoms, complications and finally progression to kidney failure.
What is dialysis and when is it used?
Dialysis is a mode of ‘kidney replacement therapy’. With our own kidneys we dialyse 24 hours a day. There are different types of dialysis treatment but essentially it’s trying to mimic the role of the kidneys by helping to remove toxins and excess fluid. While dialysis is life supporting, often quality of life is significantly impacted.
Some people will [go on to] receive a kidney transplant [which is] another form of kidney replacement therapy and like our own kidneys with a kidney transplant, you dialyse for 24 hours per day. Transplantation offers the best quality and quantity of life for someone with kidney failure, however is not appropriate for everyone as there are significant complications with transplantation to consider.
When someone needs dialysis or a transplant is determined by symptoms and their kidney function. A ballpark figure is [when they have only] around 10 per cent of kidney function, although this does vary.
How can medications affect kidney health?
There are many medications that are problematic for kidney health and for those with kidney disease. Over time [some] cause damage within the kidney: some of these [adverse reactions] can be predicted, however some can occur randomly. It is important that if you are on prescription medications that kidney function is monitored.
Non-prescription medications are not necessarily safe either. For example, in the past Bex was sold as a headache reliever and it was an Australian nephrologist that showed it was toxic to the kidney.
If you have kidney disease then the dose of medications may need to be adjusted and some medications may cause further damage. For example, if you have significant kidney disease then anti-inflammatory medications may not be recommended. Paracetamol however is generally very safe in the setting of kidney disease.
Some herbal medications can cause kidney damage [but] not in everyone. It is always important to consider the risk, benefit and need of medications. If you have CKD it’s important to talk to your doctor or pharmacist before taking any new medications – particularly ones you buy over the counter such as painkillers and vitamins.
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