Although most people have two kidneys, only one kidney can function just as well as two. You may need to take precautions to avoid injury and see a doctor for regular kidney health tests.
If you have only one kidney, it’s important to protect it and keep it functioning well because you don’t have a second to take over if it should fail.
Maintaining a healthy lifestyle by eating a nutritious diet, exercising regularly, and getting regular checkups with your doctor will help keep your one kidney healthy.
One kidney can filter enough blood to keep your body functioning as expected. This is why you can survive with only one kidney.
The recommendations for living with one kidney are the same for people with two kidneys:
- eating a balanced diet
- exercising regularly
- maintaining a moderate weight
- drinking water and staying hydrated
- maintaining moderate blood pressure, blood sugar, and cholesterol levels
- seeing your doctor regularly for physicals and kidney tests
- knowing your family medical history
- avoiding smoking if you smoke, or asking your doctor about smoking cessation
Most people with a single kidney live a typical life without developing any long- or short-term problems. One kidney can work as well as two, according to the National Kidney Foundation (NKF).
But if your kidney stops working, usually after 25 years or more, you may:
- develop high blood pressure (hypertension)
- lose protein in your urine (proteinuria)
- retain fluid
This is because you don’t have a backup kidney to compensate for a loss of function.
If your kidney loses some function, it’s typically not severe and won’t impact your life span. Some people, however, may develop the progressive loss of kidney function, or chronic kidney disease (CKD).
High blood pressure may be a sign of kidney dysfunction. It can damage the blood vessels in your kidney, potentially worsening kidney dysfunction.
Be extra careful about keeping your one kidney functioning well. This includes:
- protecting it from injury
- avoiding medications that can be harmful, such as nonsteroidal anti-inflammatory drugs
If you have a single kidney, injuring it can be a big problem because there isn’t another one to compensate for the loss of function. If the injury is severe and your kidney stops working completely, you’ll need dialysis or a kidney transplant.
Avoid playing any contact sports that could lead to kidney injury. If you do play contact sports, padding and other protective gear make kidney injury less likely, but they don’t eliminate the risk. Try to avoid other high risk activities or perform them with extra caution.
Over the long term, unless your kidney gets injured, loss of function in your single kidney is usually mild and unnoticeable.
Most people with a single kidney, after donating one, don’t need to follow a special diet. But, like people with two functioning kidneys, you should eat a balanced diet. This includes eating more fruits and vegetables and less ultra-processed foods.
Staying hydrated and drinking water when thirsty is better than overhydration or dehydration. But you may have to limit how much fluid you drink.
If you have a CKD, to prevent buildup because your one kidney can’t remove the following nutrients from your blood well, you may need to limit:
You might also need to change your diet if you’re managing other conditions, such as high blood pressure or diabetes.
Talk with your doctor or a registered dietitian about your nutritional needs and dietary restrictions.
If you’re unsure where to find a healthcare professional, try Healthline’s FindCare tool.
Alcohol affects several of your body’s organs, including your kidneys. Drinking in moderation (one drink a day for women and two drinks a day for men) usually won’t harm your kidneys.
Alcohol increases how much urine you produce and reduces your kidney’s ability to filter blood. This disrupts the fluid and electrolyte balance in your body, and you become dehydrated.
Without enough fluid, your organs and kidneys can’t function properly, which eventually may cause permanent damage.
Your liver is also important for maintaining your fluid and electrolyte balance. According to the American Kidney Fund, liver damage from excessive alcohol interferes with this balance, making it even harder for your kidneys to work correctly.
Alcohol has this effect whether you have one or two kidneys, but it may lead to kidney failure more quickly when you only have one functioning kidney.
Dialysis performs the function of your kidneys by filtering your blood and removing waste and extra fluid. It’s only done when you’ve temporarily or permanently lost most or all of your kidney function.
According to NKF, you should start dialysis only if your kidneys have lost 85% to 90% of their function. Since you usually have typical kidney function when you have just one kidney, you won’t need dialysis unless your kidney fails.
You should see your doctor at least once a year to evaluate your kidney. At this checkup, your doctor will:
- perform kidney function blood tests
- check your blood pressure
- test your urine for leaking protein
The two tests your doctor will use to evaluate your kidney function are:
- Glomerular filtration rate: This test indicates how well your kidneys filter blood. It’s calculated using the creatinine level in your blood.
- Urine test: Also called the urine albumin-to-creatinine ratio, this test measures the amount of protein in your urine to determine whether your kidney’s filters are damaged and leaky. A high protein level is a sign of kidney dysfunction.
If a problem develops or the tests indicate a problem with your kidney, you should have more frequent checkups.
Lifestyle changes and medication can lower your blood pressure and avoid further kidney damage. Speak with your doctor about what you can do.
According to the National Institute of Diabetes and Digestive and Kidney Health,
If your solitary kidney faces injury and stops working, you might be eligible for a transplant.
A kidney transplant is only done when you have no functioning kidneys. If you receive a transplanted kidney, you’ll likely regain most of your kidney function, if not all. You’ll no longer require dialysis and have typical kidney function.
No matter how many kidneys you start with, you only receive one kidney in a transplant. But you may have more than one transplant if your original transplant function fails.
Transplanted kidneys may increase in size over time. Eventually, your single transplanted kidney may function as well as two kidneys.
You don’t need two functioning kidneys to lead a healthy lifestyle. One can work just as well as two, so long as you take care of it by eating a balanced diet, seeing your doctor regularly, and limiting alcohol.
Keeping one kidney healthy isn’t very different than it would be to keep two kidneys healthy.
Avoid contact sports and other activities that could cause injury to your one kidney. This is one of the most important things you can do to keep it functioning well.
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