Being aware of the causes of kidney failure is the first step to prevention.
Dr Akira Wu, renal physician at Mount Elizabeth Hospital, explains what kidney failure is, what causes it and what symptoms to look out for.
What is kidney failure?
When kidney failure (also called renal failure) occurs, the kidneys are unable to filter waste products from the blood. Over time, dangerous levels of wastes may accumulate in the body, which can be life-threatening if left untreated.
Significant damage to your nephrons may reduce your kidney function. Doctors diagnose chronic kidney failure if lack of function persists for more than 3 months.
Stages of kidney failure
There are 5 stages of kidney disease based on how well the kidneys can filter waste out of the blood. This is measured by the estimated glomerular filtration rate (eGFR). The stages of kidney disease are based on the eGFR number:
Stage 1 kidney disease means you have mild kidney damage and an eGFR of 90 or greater. This means your kidneys are healthy and working well but you have other signs of kidney damage, such as protein in your urine or physical damage to your kidneys.
Stage 2 kidney disease refers to mild kidney damage and an eGFR between 60 and 89. This means that like in Stage 1, your kidneys are generally healthy and working well but there are other signs to indicate kidney damage such as protein in the urine or physical damage to the kidneys.
Stage 3 kidney disease is divided into 2 stages. Stage 3a refers to an eGFR between 45 and 59 while stage 3b means you have an eGFR between 30 and 44. People with Stage 3 kidney disease usually do not have any symptoms. There may also be other health complications as waste build-ups in the body, high blood pressure, anaemia and bone disease.
Stage 4 kidney disease indicates an eGFR between 15 and 29. This means that the kidneys are moderately or severely damaged. Many people with stage 4 disease have symptoms such as swelling in the hands and feet, back pain, and urinating more or less than normal. People with Stage 4 disease should also begin discussing about preparing for kidney failure with their doctor.
Stage 5 disease means the eGFR is less than 15. This means the kidney are getting very close to failure or have completely failed. Once kidney failure occurs, kidney dialysis or a kidney transplant is needed.
What causes chronic kidney failure?
Kidney failure can be attributed to several causes, such as:
- Certain diseases
- Exposure to environmental pollutants or certain medications
- Severe dehydration
- Kidney injury
Diabetes is by far the common cause of chronic kidney failure in Singapore. In fact, in 2013, over 60% of kidney failure patients who required dialysis were diabetic.
When blood sugar binds to proteins, it makes them 'sticky'. And when blood sugar levels are high, there are more sticky proteins. These attach to the kidney filters, causing damage that results in an inability to filter toxins out of the body.
The second common cause of chronic kidney failure is an inflammation of the kidney filters, known as glomerulonephritis. This condition, which can affect all ages, is not preventable or curable. However, it can be controlled with medication. Examining the urine for blood and protein is the best way to detect it.
Autosomal polycystic kidney disease (APKD)
Finally, autosomal polycystic kidney disease (APKD) is an inherited condition that can subsequently result in chronic kidney failure. If a parent is affected by APKD, there is a 50% chance their child will also have it. Symptoms include high blood pressure in young individuals, and enlarged kidneys detected by examination of the stomach or by routine ultrasound examination. The most reliable clue to diagnosis is a strong family history of the disease.
Other causes of kidney failure
Several other factors may cause chronic kidney failure, such as:
- High blood pressure. Poorly controlled blood pressure damages blood vessels in the kidneys, causing them to not work well to remove wastes and extra fluid from the body.
- Interstitial nephritis. Inflammation of the kidney's tubules and its surrounding structures.
- Urinary tract obstruction. Prolonged urinary tract obstruction due to conditions such as enlarged prostate, kidney and some cancers.
- Vesicoureteral reflux. A condition that causes urine to back up into the kidneys.
- Infection of the kidneys that is recurrent.
- Poisoning from heavy metals, such as lead or drugs that are toxic to the kidneys.
What are the symptoms of chronic kidney failure?
Symptoms of chronic kidney failure include the following:
- Nausea or vomiting
- Changes in urination
- Fluid retention causing leg swelling
- Loss of sleep
- Poor appetite
- Upset stomach
- Weakness or fatigue
- Difficulty concentrating and reduced mental sharpness
- Muscle twitches and cramps
- Persistent itching
- Chest pain
- Shortness of breath
- High blood pressure that is difficult to control
Early signs of kidney failure
Early stages of chronic kidney failure may not display any symptoms. Many of the early signs can also be confused with other illnesses and conditions. These are some of the early symptoms to look out for:
- Nausea and vomiting
- Loss of appetite
- Chest pain
- Uncontrollable high blood pressure
- Unexpected weight loss
How do doctors diagnose chronic kidney failure?
Chronic kidney disease can sometimes be a 'silent' condition. There may be no obvious symptoms until the disease is quite advanced. However, high blood pressure can sometimes be an indicator.
Doctors may diagnose chronic kidney failure with:
A simple test to show if there is blood or excess protein in the urine
- Urine microalbumin test
A separate urine test to look for microalbumin in the kidneys, a type of protein that is not normally found in the kidneys unless there is damage present
- Blood test
A blood test to check for rising creatinine levels, which indicates the degree of kidney failure
- Filtration rate test
A filtration rate test to determine how many toxins are actually being filtered by your kidneys
How do you prevent chronic kidney disease from getting worse?
If kidney disease is diagnosed early, treatment can slow the progression of the disease.
Healthy blood sugar levels
Diabetic individuals with both microalbumin in the urine and high blood pressure will benefit from establishing healthy blood sugar, blood pressure and cholesterol levels, which can reduce the risk of kidney disease by 60% and death by 50%.
Once chronic kidney failure is confirmed by blood tests, doctors may prescribe a low-protein diet. This can help to reduce the kidneys' workload. To balance out the lack of protein in the body, doctors often recommend taking amino acid tablets or other supplements.
Lower blood pressure
Blood pressure medication can help to lower blood pressure and provide additional kidney protection. Taking sodium bicarbonate supplements may also help to reduce acidity in the blood, which can slow down kidney deterioration.
Avoiding certain painkillers that are toxic to the kidneys is important in preventing further kidney damage.
Meanwhile, lowering cholesterol can help to prevent heart attack and stroke in chronic kidney failure patients who are not receiving dialysis yet.
Treatment for end-stage kidney failure disease
When chronic kidney failure reaches end-stage, dialysis helps to remove the waste that inevitably builds up in the blood.
Kidney dialysis: Haemodialysis
There are 2 types of dialysis. The first, haemodialysis, is known as 'blood washing'. A dialysis machine filters the blood and then infuses it back into the body. Typically, patients undergo a 4-hour haemodialysis session at least 3 times a week in a dialysis centre, or more rarely at home. To connect to the dialysis machine, doctors will either join a vein to an artery in the patient's arm, called an AV fistula, or surgically implant a catheter in the chest.
Kidney dialysis: Peritoneal dialysis
Peritoneal dialysis, sometimes called 'water dialysis', is the second type. Patients usually have this treatment at home every day. Doctors will surgically insert a permanent tube into the stomach to pump and then drain 2 litres of special solution into the body, 4 times a day. An automated machine can also complete these 10-litre exchanges continuously over 8 hours at night, giving patients dialysis-free days.
Doctors may ultimately use a kidney transplant to treat end-stage kidney failure. This is done by placing a healthy kidney from a living or deceased donor. Only one donated kidney is needed to replace two failed kidneys. Several tests need to be performed to determine whether a donated kidney is a suitable match for the patient. If successful, the new kidney can normalise kidney function and reverse kidney failure.
Treatment for complications of kidney failure
Kidney disease may cause several complications that need to be managed to help you feel more comfortable. Some of these complications and ways to manage them include:
Several treatment options are available to manage anaemia depending on its cause, such as medicines and iron supplements or a red blood cell transfusion.
High phosphorus and bone disease
Several medications such as a phosphate binder and calcitriol supplements can be taken to manage phosphorus levels. You should also limit the amount of phosphorus you consume daily. Exercising and not smoking also help with managing phosphorus levels and preventing bone disease.
Medicines that control heart disease or high blood pressure include diuretics, ACE inhibitors, beta blockers and aldosterone receptor blockers. Your doctor may also recommend an exercise and diet programme to manage your heart disease.
High potassium can be treated through diet and medicine. Medicines for high potassium are called potassium binders that helps to prevent potassium from building up in the blood.
Fluid intake can be limited by following a low-salt diet. Additionally, if you are thirsty, try sucking on an ice cube or a hard candy instead of drinking water. Keep track of your daily fluid intake to help you keep within your daily limit. Remember that foods, such as ice cream and soups count as liquid.
Quick facts on kidney disease
- Early detection is the best way to prevent progressive kidney disease.
- Diabetic kidney disease is the main cause of end-stage kidney failure, and typically requires dialysis or kidney transplantation.
- A healthy lifestyle can reduce the risk of developing kidney failure.
If you have questions or concerns about kidney failure, consult your doctor.