Although most people have two kidneys, you only need one functioning kidney to live an active, healthy life. You may need to take some precautions to avoid injury to your kidney.

If you have only one kidney, it’s important to protect it and keep it functioning well because you don’t have a second one to take over if it fails.

Maintaining a healthy lifestyle by eating a nutritious diet, exercising regularly, and getting regular checkups with your doctor helps keep your kidney healthy.

Keep reading to learn more about living with one kidney.

Your kidneys filter out waste and extra fluid from your blood so it can be excreted from your body in your urine.

One kidney can filter enough blood to keep your body functioning normally. This is why you can survive and be healthy with only one kidney.

The recommendations for healthy living if you have only one kidney are basically the same for people with two kidneys. They include:

In addition, if you have a solitary kidney, you should be extra careful about keeping it functioning well. This includes:

Reasons for having one kidney

There are a number of reasons you may have just one kidney. These include the following:

  • You were born with only one kidney.
  • One of your kidneys was removed (nephrectomy) to treat a medical condition or injury.
  • You’ve had a kidney transplant.
  • You donated a kidney to someone who needed a transplant.

You can also have two kidneys but only one that functions, which is the same as having a single kidney.

One big difference in outcomes of having one kidney relates to whether you were born with just one kidney versus having lost or donated one.

For those born with one kidney, the solitary kidney does the job of both kidneys from day one, often growing into a larger and better functioning kidney.

When one kidney is removed or donated, the other kidney does not compensate, and therefore the overall kidney function is decreased by half.

Your kidneys play a role in maintaining fluid balance in your body, keeping protein in your blood, and controlling your blood pressure.

If your kidneys stop working, you may:

Most people with a single kidney live a normal life without developing any long- or short-term problems.

However, the risk of developing mild high blood pressure, fluid retention, and proteinuria is slightly higher if you have one kidney instead of two. This is because a second kidney can compensate and make up for a kidney that has lost some function.

Since it has no backup, the loss of function of a single kidney could lead to proteinuria, fluid retention, or high blood pressure earlier than if you had two kidneys.

Protecting your single kidney from injury

If you have a single kidney, injuring it can be a big problem because there isn’t another one to compensate. If the injury is severe and your kidney stops working completely, you would need dialysis or a kidney transplant to survive.

To avoid this, it’s very important to protect your single kidney from injury. Avoid contact sports that could lead to kidney injury. These include:

  • boxing
  • football
  • hockey
  • martial arts
  • rugby
  • soccer
  • wrestling

If you do play contact sports, wearing padding and other protective gear makes kidney injury less likely, but doesn’t eliminate the risk completely.

Other high-risk activities must be avoided or done with extra precautions. These activities include:

  • rock climbing
  • water sports like jet skiing or water skiing
  • motorcycle riding
  • motorsports like racing
  • horseback riding
  • bungee jumping
  • skydiving

Over the long term, unless your kidney gets injured, loss of function in your single kidney is usually very mild and unnoticeable.

Most people with a single kidney don’t need to follow a special diet, but like people with two kidneys, you should eat a healthy balanced diet.

Staying normally hydrated and drinking when thirsty is better than overhydration or dehydration.

If you have a single kidney because you had a transplant or if you have kidney disease, you may need to limit the amount of sodium, phosphorous, and protein in your diet. This is because your kidney can’t remove them from your blood very well, so they build up.

You may also have to limit the amount of fluids you drink.

Talk to your healthcare provider about your nutritional needs and dietary restrictions.

Importance of a healthy lifestyle

Whether you have one or two kidneys, you should strive to live a healthy lifestyle along with eating a healthy diet. This includes:

  • not smoking
  • getting regular exercise
  • maintaining a healthy weight
  • staying hydrated
  • limiting alcohol
  • reducing stress

Many of your body’s organs are affected by alcohol 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 the amount of urine you produce but 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 in your body, the cells in your organs, including your kidneys, can’t function properly. Eventually it may cause permanent damage.

Your liver is also important for maintaining fluid and electrolyte balance. Liver damage from excessive alcohol interferes with this balance, making it even harder for your kidneys to work correctly.

The risk of kidney damage is even higher for heavy drinkers who also smoke.

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 kidney 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 the National Kidney Foundation, dialysis should be started only if your kidneys have lost 85 to 90 percent of their function. Since you usually have nearly normal kidney function when you have one kidney, you won’t need dialysis unless your kidney fails.

You should see your healthcare provider at least once a year to evaluate your single kidney. If a problem develops, you should be checked more often.

Two tests are used to evaluate your kidney function:

  • The glomerular filtration rate (GFR) indicates how well your kidneys are filtering blood. It’s calculated using the creatinine level in your blood.
  • The amount of protein in your urine is measured to determine if the filters in your kidney are damaged and leaky. High levels of protein in your urine is a sign of kidney dysfunction.

Your blood pressure also must be measured.

High blood pressure can be a sign of kidney dysfunction. It can also damage the blood vessels in your kidney, which can make kidney dysfunction worse.

Lifestyle changes and medication can lower your blood pressure and avoid further kidney damage.

According to the National Institute of Diabetes and Digestive and Kidney Health, almost 200,000 people in the United States have a functioning transplanted kidney.

A kidney transplant is only done when you have no functioning kidneys. The risks of the procedure and side effects of the medications you’ll need for the rest of your life outweigh the small increase in function you get from a second kidney.

If your solitary kidney gets injured or sick and stops working, you might be eligible for a transplant.

No matter how many kidneys you started with, you only receive one kidney in a transplant. The transplanted kidney usually gets bigger and works harder over time. Eventually, your transplanted kidney will function almost as well as two kidneys.

Most people with a single kidney lead normal, healthy lives. Whether you have one kidney or two, a healthy lifestyle is important to keep them functioning well.

This includes eating a healthy diet, getting regular exercise, maintaining a healthy weight, limiting alcohol, staying hydrated, and seeing your healthcare provider at least once a year.

Avoiding contact sports and other activities that could cause an injury is one of the most important things you can do to keep your single kidney functioning well.