Kidney disease is any condition that affects the functioning of your kidneys. Chronic kidney disease refers to kidney damage that happens slowly and in stages.
- Diabetes and untreated high blood pressure are the most common causes of chronic kidney disease (CKD).
- Maori and Pasifika people with diabetes have an increased risk of chronic kidney disease.
- Because most people don’t have symptoms in the early stage, see your doctor regularly if you are at risk.
- Early detection and treatment can prevent or slow the condition.
- CKD is a silent condition (it has no pain or obvious symptoms) so risk factors (such as diabetes and high blood pressure) need to be checked for regularly.
- Treatment includes changes to your lifestyle and diet, and medication, and may also include dialysis.
- Good blood pressure and diabetes control can protect your kidneys and also slow damage if disease develops.
What causes kidney disease?
Your kidneys filter and remove waste and water from your bloodstream. The two most common causes of kidney disease are diabetes and high blood pressure as they damage parts of your kidneys.
When your blood sugar is raised, it causes damage to many blood vessels in your body, including the blood vessels in your kidneys. About 1 in 3 people with diabetes will end up with some kidney damage. Diabetic kidney disease is also called diabetic nephropathy.
High blood pressure
High blood pressure damages the small vessels that take blood to the kidney filters and can also damage the filters themselves. Read more about blood pressure and kidney disease.
- Glomerulonephritis is a group of diseases that affects the filtering units in your kidneys.
- Polycystic kidney disease causes cysts to form in your kidneys. This is an inherited disease, which means that it is passed down from your parents.
- Lupus and other diseases that affect your body’s immune system can also affect your kidneys.
- Obstructions caused by abnormally shaped ureters, kidney stones, tumors or an enlarged prostate gland can affect your kidneys.
- Repeated urinary tract infections (UTIS) can also affect your kidneys.
What are the symptoms of chronic kidney disease?
CKD is called a silent disease because it often causes no symptoms. It is not uncommon to lose up to 70% of kidney function before developing symptoms.
The first signs may be general and can include:
- poor appetite and weight loss
- muscle cramps
- a need to pee more often than usual
- pain or burning when peeing
- blood in your pee
- puffiness or swelling around your eyes and ankles.
How is chronic kidney disease diagnosed?
One of the main ways kidney disease is diagnosed is by the presence of albumin in your pee (urine). Albumin is a protein found in your blood. A healthy kidney doesn’t let albumin pass from your blood into your urine. A damaged kidney lets some albumin pass into your urine. The less albumin in your urine, the better. Sometimes albuminuria is also called proteinuria.
Albumin in your pee is detected using a urine dipstick. Read more about albumin in the urine. Having protein in your pee also increases your chance of having a heart attack, stroke and/or high blood pressure.
- Blood tests – these measure blood levels of creatinine and urea. Both of these are normally excreted in your pee, but if your kidneys are not functioning properly, increased amounts can be found in your blood. Read more about kidney function blood tests.
- Renal imaging – this involves taking a picture of your kidneys using methods such as ultrasound, CAT scan or magnetic resonance imaging. These tests help work out if there are any unusual growths or blockages to the flow of pee.
- Renal biopsy – this is a hospital procedure in which a needle is inserted through your skin into your kidney. A small sample of kidney tissue is removed to be looked at under a microscope.
How is chronic kidney disease treated?
When kidney disease is detected early, changes to lifestyle and diet can slow the disease and prevent serious consequences.
There are also specific medications available that can slow or prevent the progression of kidney failure.
Your treatment will depend on what stage of kidney disease you have and what caused it in the first place.
- Stages 1 to 2 (early to moderate kidney failure) – the treatment is to reduce blood pressure, keep diabetes well controlled and take medication such as ACE inhibitors to reduce further damage to your kidneys.
- Stage 3 (glomerular filtration rate less than 60) – in addition to the above, you will also be referred to a nephrologist (kidney specialist).
- Stages 4 to 5 (renal failure) - dialysis, renal transplantation or supportive measures are generally needed. Read more about renal failure.
What can I do to slow damage to my kidneys?
It is important to prevent your kidneys becoming damaged further.
- Have your blood pressure checked at least once a year.
- Have your blood sugar checked for diabetes.
- Don't smoke – there is no safe level of smoking and it damages your blood vessel walls.
- Check your cholesterol levels (high cholesterol damages blood vessels in you kidneys).
- Maintain your weight within a healthy range for your height with a well-balanced diet. Read more about chronic kidney disease and nutrition.
- Regular exercise also helps control your weight
- Have an annual check-up with a GP. If you need a blood test, ask for your kidney function to be checked. Ask for your urine to be checked for blood, protein and sugar. Read more about how to protect your kidneys.