Kidney health
Your kidneys, explained
- of blood filtered every day
- ~140 Lof blood filtered every day
- of it becomes urine
- 1–2 Lof it becomes urine
- tiny filters in each kidney
- 1 milliontiny filters in each kidney
Where they are
Where are your kidneys?
- At the back of the abdomen, against the back muscles, one on each side of the spine.
- Just below the rib cage. The lowest ribs partly cover and protect the top of each kidney.
- Roughly level with the last vertebra of the chest (T12) down to the third vertebra of the lower back (L3).
- The right kidney sits a little lower than the left, because the liver is above it.
- Behind the stomach, liver, spleen and intestines, which lie in front of them.
- Pain from the kidneys, for example from a stone, is usually felt in the side or back below the ribs, and can spread to the lower belly or groin.
Seen from behind: left and right are the body's own sides.
Kidneys
Two fist-sized organs at the back of the abdomen, one on each side of the spine, just under the rib cage.
Meet your kidneys
Two small organs with a big job
Kidneys
Two bean-shaped organs, each about the size of a fist, just below the rib cage on either side of the spine. Each one holds about a million tiny filters called nephrons.
How they filter
How your kidneys clean your blood
What they do
Six jobs your kidneys do every day
Remove waste
Filter out waste from food, muscle activity and medicines.Why it matters: If waste builds up in the blood, people can feel tired, sick and itchy, and lose their appetite.
Balance water
Keep just the right amount of fluid in the body, making more or less urine as needed.Why it matters: When the kidneys can't remove extra fluid, it can cause swelling in the legs and face, and breathlessness.
Balance minerals
Keep sodium, potassium, calcium and phosphorus, and the blood's acid level, in a healthy range.Why it matters: Potassium that is too high or too low can upset the rhythm of the heart.
Control blood pressure
Release hormones and adjust salt and water to help keep blood pressure steady.Why it matters: Kidney disease can raise blood pressure, and high blood pressure can damage the kidneys, so each can make the other worse.
Help make red blood cells
Make a hormone (erythropoietin, or EPO) that tells the bone marrow to make red blood cells.Why it matters: Without enough EPO, people can develop anaemia and feel weak and tired.
Keep bones strong
Turn vitamin D into its active form and help balance calcium and phosphorus.Why it matters: Over time, kidney disease can weaken the bones.
Warning signs
Signs your kidneys may need attention
Early kidney disease usually has no symptoms. Many people only find out from a urine or blood test, so if you are at risk, don’t wait for signs.
- Foamy or bubbly urine, which can be a sign of protein in it
- Blood in the urine: pink, red or cola-coloured
- Needing to pass urine more or less often, especially at night
Get help straight away if you have
- Passing very little or no urine
- Severe pain in the side or back, especially with fever, vomiting or blood in the urine
- Fever and chills with burning when passing urine, or back pain
- Sudden swelling with shortness of breath
In a medical emergency, call 112 or go to the nearest emergency department.
Conditions
Common kidney conditions
Chronic kidney disease (CKD)
A slow loss of kidney function over months or years. It often causes no symptoms until it is advanced, which is why testing matters for people at risk. Treatment can slow it down.
Nephrology & kidney careAcute kidney injury (AKI)
A sudden drop in kidney function over hours or days, for example from severe dehydration, serious infection, some medicines or a blockage. It needs urgent care and can often get better with prompt treatment.
Kidney stones
Hard deposits that form from minerals in the urine. A stone moving down can cause severe pain in the side or back and blood in the urine. Drinking enough water helps prevent them.
UrologyUrinary tract and kidney infections
Bacteria in the urinary tract can cause burning and frequent urination. If the infection reaches the kidneys it can cause fever and back pain, and needs prompt treatment.
Diabetic kidney disease
High blood sugar over many years can damage the kidneys' filters. It is one of the most common causes of kidney failure. Good sugar and blood pressure control, and regular kidney tests, help protect the kidneys.
High blood pressure
Over time, high blood pressure can damage the blood vessels in the kidneys. Together with diabetes, it is a leading cause of kidney disease.
Polycystic kidney disease
An inherited condition in which many fluid-filled cysts grow in the kidneys and can affect how well they work over time.
Glomerulonephritis
Inflammation of the kidneys' tiny filters. It can cause blood or protein in the urine, swelling and high blood pressure.
Kidney failure
When the kidneys can no longer keep up with the body's needs. Treatment is dialysis, where a machine or the lining of the abdomen filters the blood, or a kidney transplant.
Renal transplant services
Do's & don'ts
Simple ways to protect your kidneys
Do
- Keep blood pressure in checkHave it measured regularly and follow the treatment your doctor recommends.
- Manage blood sugarIf you have diabetes, keeping sugar levels in your target range protects your kidneys.
- Drink enough waterUnless your doctor has told you to limit fluids, as can happen with advanced kidney disease or dialysis.
- Eat less saltChoose fresh food over pickles, papads, packaged snacks and other salty processed foods.
- Stay active and keep a healthy weightRegular exercise helps blood pressure, blood sugar and weight.
- Get checked if you are at riskA simple urine test and blood test can find kidney disease early.
Avoid
- Take painkillers regularly without adviceFrequent or high doses of painkillers such as ibuprofen, diclofenac or naproxen can harm the kidneys.
- Use unprescribed remedies or supplementsSome herbal products and supplements can damage the kidneys. Ask your doctor first.
- SmokeSmoking damages blood vessels, including those in the kidneys.
- Drink too much alcoholHeavy drinking raises blood pressure and puts extra strain on the body.
- Ignore warning signsChanges in your urine, swelling or burning when passing urine are worth checking.
- Stop or change medicines on your ownTalk to your doctor before changing any prescribed treatment.
Myth or fact
Test what you know
Statement 1 of 7
“If my kidneys were failing, I would feel it.”
See all the answers
If my kidneys were failing, I would feel it. (myth)
Early kidney disease usually has no symptoms. Urine and blood tests are the only way to know.
Diabetes and high blood pressure are the most common causes of kidney disease. (fact)
They are the two leading causes. Keeping both under control is one of the best ways to protect your kidneys.
Drinking lots of water can cure kidney disease. (myth)
Enough water helps healthy kidneys and helps prevent stones, but it does not cure kidney disease. Some people with advanced disease need to limit fluids.
Common painkillers are always safe for the kidneys. (myth)
Regular or high doses of painkillers such as ibuprofen and diclofenac can harm the kidneys, especially in people already at risk.
Herbal or 'natural' remedies can't harm the kidneys. (myth)
Some herbal products and supplements can damage the kidneys. Check with a doctor.
Kidney disease can often be slowed if it is found early. (fact)
Finding it early gives the best chance to slow it down with treatment and healthy habits.
A person can live a full, healthy life with one healthy kidney. (fact)
One healthy kidney can do the work of two for most people.
Am I at risk?
Check your risk factors
Tick anything that applies to you.
Nothing ticked? Keep up healthy habits, and ask your doctor about your kidneys at regular check-ups.
This checklist is not a diagnosis, and nothing you tick is stored or sent anywhere.
Simple tests that check your kidneys
Urine albumin test
Checks for a protein called albumin in the urine, one of the earliest signs of kidney damage.
Blood creatinine and eGFR
Measures a waste product in the blood to estimate how well the kidneys are filtering (the eGFR).
Blood pressure
High blood pressure can both cause and signal kidney problems.
Questions about your kidneys?
Call the hospital to ask about a kidney check-up, or walk in. Appointments are by phone or walk-in only.