Overview
The kidneys filter waste and extra fluid out of the blood, control the balance of salts, help manage and help make red blood cells. Chronic kidney disease means they are damaged and cannot do this as well as they should.
It is common with age, and more common in people of South Asian and Black backgrounds. It is described in stages, based on how well the kidneys filter, with higher numbers meaning more loss of function.
Symptoms
Early kidney disease usually causes nothing at all. When the disease is more advanced, symptoms can include:
- Tiredness
- Swollen ankles, feet or hands
- Shortness of breath
- Feeling sick and losing your appetite
- Blood in the urine
- Needing to pass urine more often, especially at night
- Itchy skin
- Muscle cramps
- Difficulty sleeping
When to see a doctor
See a doctor about persistent or worrying symptoms that could be caused by kidney disease, such as swollen ankles, blood in the urine or constant tiredness. If you have diabetes or high , ask how often your kidneys should be tested.
Causes
Diabetes and high are the two most common causes. High blood sugar damages the tiny filters in the kidney, and high blood pressure damages the blood vessels that supply them.
Other causes include high , repeated kidney infections, inflammation of the kidney, inherited polycystic kidney disease, blockage of the flow of urine by stones or an enlarged prostate, and long term use of medicines such as anti-inflammatory painkillers and lithium.
Risk factors
- Diabetes
- High
- A family history of kidney failure
- Older age
- South Asian or Black background
- Repeated kidney infections or kidney stones
- Regular use of anti-inflammatory painkillers
Complications
- Heart and blood vessel disease, which is the leading cause of death in people with kidney disease
- Anaemia, causing tiredness and breathlessness
- Weak bones and problems with minerals such as calcium and phosphate
- A high level of potassium in the blood
- Kidney failure, needing or a transplant
Prevention
- Keeping and blood sugar in the range your doctor sets
- Having kidney blood and urine tests if you are at higher risk
- Eating less salt, and following any diet advice you are given
- Not smoking or using tobacco
- Checking with a doctor or pharmacist before taking regular painkillers or supplements
Diagnosis
Two tests are used together. A blood test measures creatinine, a waste product from muscle, and from it doctors estimate the filtering rate (eGFR). An eGFR of 60 or above is in the normal range, below 60 may mean kidney disease, and 15 or below means kidney failure.
A urine test measures albumin, a protein that leaks through damaged filters, as a ratio with creatinine. Above 30 mg per gram may mean kidney disease. An scan and, occasionally, a kidney may follow. People with diabetes are usually tested once a year.
Treatment
Treatment aims to slow the damage and reduce the risk to the heart. medicines that also protect the kidneys are commonly used, along with treatment for diabetes and . Diet advice often covers salt, and sometimes protein, potassium and phosphate.
Anaemia, bone problems and fluid build up are treated as they appear. Doses of many medicines need adjusting when kidney function is reduced.
If the kidneys eventually fail, filters the blood by machine or through the lining of the abdomen. A kidney transplant is the other option, and planning for either starts well before it is needed.
Myths and facts
Things people often say about this. Open each one to see what is true.
Myth“I would know if my kidneys were failing.”What is true?
Fact
Kidney disease is quiet. Many people have no symptoms at all until it is well advanced, because the kidneys keep working reasonably well until a large amount of function is lost. Testing is the only way to know, which is why people with diabetes or high blood pressure are tested regularly.
Myth“Ordinary painkillers are harmless, so I can take them whenever I need to.”What is true?
Fact
Long term use of some medicines, including anti-inflammatory painkillers and lithium, is one of the causes of kidney damage. If you have kidney disease, ask a doctor or pharmacist before taking any regular pain relief, and tell them about anything you buy without a prescription.
Myth“Once the kidneys are damaged nothing can be done until dialysis.”What is true?
Fact
Treatment cannot cure kidney disease, but it can slow it down, sometimes for many years. Controlling blood pressure and blood sugar, taking kidney protecting medicines, treating cholesterol and making changes to diet all reduce further damage.
Myth“A diagnosis of kidney disease means dialysis is coming.”What is true?
Fact
Only a small number of people with chronic kidney disease go on to complete kidney failure. Most live a normal life span with treatment and monitoring. People with kidney disease do have a higher risk of heart and blood vessel disease, so that is treated too.
Questions to ask your doctor
Tick the ones you want answered and take them with you.
Common questions
Can kidney damage be reversed?
Damage that has already happened cannot usually be undone, but treatment can slow or sometimes halt further loss. The earlier it is found, the more kidney function there is to protect, which is why testing people at risk matters.
Do I need to drink more water to protect my kidneys?
Drinking sensibly is fine, but more fluid does not repair damaged kidneys, and in advanced kidney disease too much fluid can be harmful. Ask your doctor what is right for your stage rather than following general advice.
Is dialysis the only option if my kidneys fail?
No. A kidney transplant is an option for many people, and some choose supportive care that manages symptoms without dialysis. These are discussed well in advance so there is time to prepare.
