Patient information from the BMJ Group
Chronic kidney disease
If you have chronic kidney disease, your kidneys are gradually losing their ability
to filter wastes and excess fluid from your blood. It is a serious condition, but there
are good treatments that can help slow the disease.
We’ve brought together the research about chronic kidney disease and talked to
experts about the best ways to treat it.You can use our information to talk to your
doctor and decide which treatments are best for you.
What is chronic kidney disease?
Chronic kidney disease means your kidneys are losing their ability to filter waste products
out of your blood.You may also hear it called chronic renal failure, chronic kidney
failure, or chronic renal insufficiency. Chronic means it’s a long-term condition, and
renal means it involves your kidneys.
Your kidneys are two organs located just below your ribs near the middle of your back,
with one on either side of your spine. They filter your blood, getting rid of wastes and
extra fluid, which go to your bladder as urine.
Chronic kidney disease happens when something goes wrong with this filtering process.
Usually this occurs because someone has had diabetes or high blood pressure for a
• People with diabetes have too much glucose (sugar) in their blood. Over time, this
can harm the tiny blood vessels that filter wastes in the kidneys. Diabetes is the
most common cause of chronic kidney disease.
• High blood pressure can also damage these tiny blood vessels over time. This is
the second-most common cause.
Other, less frequent causes include: blockage in the renal arteries, kidney problems that
develop in the womb, inherited diseases (such as polycystic kidney disease), autoimmune
diseases (such as lupus and scleroderma), and being around toxic substances for a long
time, including leaded paint and soldering materials.
When the kidneys start losing their filtering ability, wastes and fluid build up. This causes
problems throughout the body.
Chronic kidney disease is different from acute kidney injury, which happens when your
kidneys suddenly stop working. This can occur because of a sudden drop in the blood
flow to the kidneys, a sudden blockage of the urine flow from the kidneys, or damage
from some illnesses, drugs, or poisons. Acute kidney injury can sometimes be reversed
if the kidneys aren’t badly damaged. If you’ve had acute kidney injury, you may have a
higher risk of chronic kidney disease and end-stage kidney disease in the future.
What are the symptoms?
Many people with chronic kidney disease don’t have any clear symptoms. In fact,
symptoms often don’t appear until there has been significant damage to the kidneys.
Possible symptoms include:
• Urinating more or less often than usual
• Puffiness around your eyes or swelling in your limbs (oedema)
• Feeling generally ill
• Loss of appetite and weight loss
• Foamy-appearing urine
• Dark-coloured urine (the colour of cola)
• Rashes and itching.
Many symptoms, such as tiredness and nausea, can also be caused by other conditions.
This can make chronic kidney disease difficult to diagnose.
If your doctor suspects you could have kidney damage, they will test your blood and
urine for signs of damage, and to see how well your kidneys are filtering out waste.
You might also need an ultrasound to spot kidney stones and other blockages, or a
biopsy to look for signs of damage under a microscope.
If you do have kidney damage, your doctor will try to find out what caused it. This is
important, as treating the underlying cause can help prevent more damage.
What treatments work?
There is no cure for chronic kidney disease but treatments can slow the disease, improve
your symptoms, and reduce your risk of complications. The outlook is especially good if
you catch the kidney damage early on.
Treating the cause
Treating the underlying cause of your kidney damage is essential. For many people, this
will mean closely controlling their diabetes or high blood pressure by taking medicines
and following their doctor’s advice on diet, exercise, weight loss, smoking, and other
lifestyle factors. This can slow further damage.
© BMJ Publishing Group Limited 2015. All rights reserved.
Treating high blood pressure
High blood pressure is both a cause and consequence of chronic kidney disease. It
happens because of the fluid that builds up in your blood and tissues when your kidneys
aren’t filtering properly. If not treated, high blood pressure can cause further damage to
your kidneys and also lead to heart disease.
Most people with chronic kidney disease take blood pressure drugs.Your doctor will
probably prescribe medicines called angiotensin-converting enzyme (ACE) inhibitors
or angiotensin II receptor blockers (ARBs). These medicines should improve your
blood pressure and how your kidneys work. If these medicines don’t help enough or you
can’t take them for some reason, there are other blood pressure drugs you can try.
Your doctor may aim to lower your blood pressure below what would be normal if you
didn’t have kidney disease. Studies show this helps protect your kidneys.
Managing your cholesterol
Having chronic kidney disease puts you at higher risk of developing heart disease.Your
doctor may prescribe a statin to help lower this risk. These drugs reduce your level of
‘bad’ cholesterol, so there’s less to build up inside your blood vessels and cause heart
and circulation problems.
Treating problems caused by kidney failure
Chronic kidney disease can cause problems throughout your body. Below, we’ve described
some of the most common problems, and their treatments.You will have regular blood
and urine tests to spot many of these problems before they become serious.
• Fluid retention: Fluid can build up in your body if your kidneys aren’t working well.
This can cause swelling in your limbs (oedema), as well as high blood pressure.
Drugs called diuretics can help flush excess fluid from your body as urine.Your
doctor may also recommend restricting how much fluid and salt you consume each
• Anaemia: Anaemia is when you have too few red blood cells. This can make you
feel very tired and become breathless easily. Anaemia often happens to people with
kidney disease because the kidneys aren’t making enough of a chemical messenger
called erythropoietin (EPO). EPO helps regulate how many red blood cells your body
makes. Treatment involves getting injections with a medicine that works like EPO
(an erythropoiesis-stimulating agent). Iron is also important for making red blood
cells. So if you are low on iron, you will need to take iron tablets or have iron
• Weakened bones: Vitamin D, phosphate, and calcium are all essential for strong
bones. If your kidneys are damaged, your supply of these nutrients can get out of
balance and cause problems. In particular, your calcium level may get too low,
triggering the release of a chemical messenger called parathyroid hormone (PTH).
PTH causes more calcium to be taken from your bones, and over time this can lead
to weakened and deformed bones, and swollen joints. To prevent these problems,
many people with kidney failure take calcium and vitamin D supplements. Some
people also limit the amount of phosphate in their diet, as this can increase the
amount of calcium available for their bones. They may also take drugs called
phosphate binders, which lower the amount of phosphate in their blood.
• Too much acid: If the kidneys aren’t removing enough acid from the body, you can
get a condition called metabolic acidosis. Often there are no clear symptoms. But if
your blood becomes too acidic, this can cause serious problems such as abnormal
heart rhythms, seizures, and coma. If tests show your blood is becoming overly
acidic, you’ll be treated with an antacid called sodium bicarbonate (baking soda).
• Too much potassium: If the kidneys aren’t working properly, potassium can build
up in the blood, causing a condition called hyperkalemia. If not treated, this can lead
to abnormal heart rhythms, cardiac arrest, and problems with nerve and muscle
control.Your doctor will keep an eye on your potassium level and may recommend
limiting potassium in your diet.You may also take a diuretic to help your body get
rid of both extra fluid and potassium. If your hyperkalemia becomes severe, this is
a medical emergency requiring hospital treatment.
• Too little protein: As kidney disease worsens, more and more protein leaks into
your urine from your kidneys. This means there’s less protein to nourish your body
and you may lose weight.Your doctor may suggest changes in your diet to help with
Treating end-stage kidney disease
If your kidney damage worsens to the point where you have less than 15 percent of your
normal kidney function, you have end-stage kidney disease.This means that your kidneys
can no longer clear your body of wastes and extra fluid, and you need either dialysis or
a kidney transplant.
Doctors typically discuss these treatments with patients before they reach this stage.
That way, they’ll have a treatment plan in place once their kidneys are no longer working.
What will happen to me?
Chronic kidney disease is a serious long-term illness, but many people live with the
condition for many years. The outlook is best if your kidney damage is discovered early.
The sooner you start treatment, the sooner you can slow further damage. Some people
with kidney disease never need dialysis or a kidney transplant, and manage to stay
healthy with treatment.
But even people with advanced kidney disease can achieve a good quality of life by
closely following their doctor’s advice and treatment plan.
This information is aimed at a UK patient audience. This information however does not replace medical advice.
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