Our kidneys perform many functions that are vital to good health, but it is not unusual to have only one kidney to do the work of two.
- Many people (more commonly men) are born with a single kidney.
- Some people have to have one kidney surgically removed because they may have developed an obstruction or a tumour or sustained a severe traumatic injury after an accident.
- Some people may have received a kidney from a living or deceased donor (in a kidney transplant operation), after their own kidneys have failed.
- Others may have donated one of their kidneys to a loved one or another person with kidney failure (in a kidney transplant operation).
How is a single kidney different?
It needs more protection. Single normal kidneys tend to grow faster and get larger than normally paired kidneys. For this reason, single kidneys can be more vulnerable to injury – especially from certain heavy contact sports.
Transplanted kidneys are also less protected than other kidneys because they are usually placed into the pelvis.
So if you have one functioning kidney it may be advisable to avoid sports including:
- field hockey
- ice hockey
- martial arts
If you still want to participate in these sports make sure you are extra careful and always wear protective padding – but always seek medical advice first.
It can sometimes do the work of two
Tests have shown that some people who have had one kidney removed can have increased function in their remaining kidney. These increased function levels can equate to around 70 per cent of that normally achieved by two kidneys.
If someone is born with a single kidney, their overall kidney function is often normal.
Are there any long-term problems to living with a single kidney?
Most people with a single normal kidney have few or no problems, particularly in the first few years. However, doctors would generally recommend that people are followed up more closely than those with two normal kidneys – especially if they were born with two kidney but have had one removed.
Children who have had a kidney surgically removed may have some slightly increased chance of developing abnormal amounts of protein in the urine and some abnormality in kidney function in early adult life. Similar abnormalities have been found in individuals born with a single kidney. There is also a greater chance of developing a slightly higher blood pressure than normal. But the decrease in kidney function is usually mild, and life span is normal.
How often should someone with one kidney see their GP?
A urine test (urinalysis) and blood pressure check should be done yearly, and kidney function should be checked every few years – more often if urine tests and blood pressure readings are abnormal.
Are dietary changes needed?
In general, people with one healthy kidney don’t need special diets. However, it’s always good to:
- have a healthy well-balanced diet
- reduce your salt intake
Dietary restrictions aren’t usually necessary for people who have received a transplanted kidney but it’s still worth following a healthy diet and watching your salt intake. However, you will probably be advised to avoid fresh grapefruit or grapefruit juice because they can interfere with certain medications. If you are advised by your kidney consultant to make specific changes to your diet, ask to be referred to the renal dietitian and follow their advice.
For more information about diet and kidney disease take a look at our dietary hints and tips.
Your mental wellbeing
Living with one kidney can sometimes have emotional implications – especially if you have received a kidney from someone or if you have donated one of your kidneys.
Your mental health is as important as your physical health so try not to bottle feelings up. It can help to talk to other people in your situation, as well as to friends and family members. You could also ask your kidney unit to put you in touch with a professional counsellor or social worker.
Take a look at our support section to see what other help is available.
What about over the counter medicines?
Having one functioning kidney means that you need to be cautious about how you use non-prescription medicines – especially if you have received a transplanted kidney.
You can find detailed information about the medicines you can and can’t take in our over the counter medicines page.