Can You Live With One Kidney?

How many kidneys do you need?

While some people can be born with one kidney, most humans are born with two. You can lead a normal, healthy life with one kidney. You, however, cannot survive without any kidneys as it is an essential organ that filters out the waste and excess salts in your blood.

Can you survive with one kidney?

Yes, you can survive and even live an active, healthy life with one kidney. If only one kidney is present, it can filter as much as two kidneys would normally do. In kidney transplantation, only one kidney is harvested from the donor and given to the recipient. It can then function completely normally.

Reasons for having one kidney

There are several causes for having one kidney. They include:

Congenital disorders

You may be born with one kidney because the other kidney never developed. This condition is called renal or kidney agenesis.

You could also be born with two kidneys, one atrophied and non-functioning while the other is normal. The condition is called kidney dysplasia.

Nephrectomy

Doctors can surgically remove your kidney to treat a condition affecting the organ, such as cancer, or to deal with other diseases or injuries. This surgical removal of a kidney for such a condition is called a nephrectomy.

Kidney donation

You could also opt to give one of your kidneys to someone who has developed kidney failure and requires a transplant.

What's it like living with one kidney?

You will live the same kind of healthy life you would live with two kidneys. You could even live with a single kidney for most of your life without noticing unless the condition is detected at birth. People with one kidney show no symptoms at all, and you may only discover it through an x-ray, ultrasound, or surgery for an unrelated condition.

Can a transplanted kidney work just as well as two?

The transplanted kidney will adjust to perform the functions that would be carried by two. However, there are challenges to a transplanted kidney, such as transplant rejection. It is usual for the body to fight off anything foreign. You will need anti-rejection medication to suppress the immune system's response to the transplanted kidney.

While these medications can have side effects such as weight gain, acne, or facial hair, not everyone will experience these signs. You could, however, be more susceptible to infection due to a weaker immune system. The doctor will conduct regular tests to monitor the levels of anti-rejection medicine in your body and check your kidney function.

Complications of having one kidney

It is unlikely that you will experience complications because of having one kidney. You may, however, experience rare complications such as:

• High blood pressure

• An abnormally low glomerular filtration rate (GFR)

• High blood pressure during pregnancy

Generally, having one kidney puts you at a slight risk of developing complications if your kidney loses some function since there is no second one to compensate. The lack of a backup means you are likely to experience fluid retention, high blood pressure, and proteinuria earlier than you would if you had two kidneys.

Monitoring one kidney

If you have one kidney, you should carefully preserve it as there is no spare. You can keep it healthy by monitoring the following:

Diet

You do not need to eat a special diet if you have one kidney, but you should stick to a healthy diet. Eating healthy entails staying hydrated, limiting salt intake, and maintaining a healthy weight. 

Limiting phosphorus and protein intake is also advisable if you have kidney disease and a single kidney but should be supervised by a dietitian or doctor. Whether you have two kidneys or not, it is also advisable to maintain a healthy lifestyle that entails low alcohol intake, exercising regularly, and not smoking.

Avoid injury

Injury to your solitary kidney can prove problematic as you would need a transplant or dialysis if it loses its ability to function. Injuries could result from contact sports. Avoiding such sports or wearing protective gear to provide a cushion would be best.

Blood pressure

High blood pressure is likely to damage the blood vessels in your kidney, rendering it less efficient. A kidney with damaged blood vessels cannot adequately remove all the waste and fluid in your body. Extra fluid can increase the blood pressure even further, which could ultimately cause your kidneys to fail.

Therefore, it is vital to have your blood pressure regularly checked and drugs administered to lower it before it affects your kidneys.

Blood tests

Glomerular filtration rate (GFR) test

This test measures the creatinine levels in your blood. Creatinine is a waste product that emanates from muscle tissue. A damaged kidney will have difficulties filtering creatinine from your blood. A high creatinine level is thus an indication of kidney disease. Doctors use creatinine levels to compute the GFR,¹ which gives a more accurate view of your kidney function.

A reading of 60 is in the normal range, whereas anything below that may suggest that you have kidney disease and need further examination. A GFR reading of 15 or less means that your kidney has lost function, and you need to be on dialysis or have a transplant.

Blood urea nitrogen (BUN)

Urea nitrogen² is a waste product resulting from the breakdown of protein in the liver. The blood carries the waste product to the kidney, where it is filtered. If your kidney is not functioning correctly, the urea will remain in the blood and can be detected using the BUN test.

A BUN level of 7–21 mg/dL³ is considered normal, but unless the level exceeds 60 mg/dL, this test may not give much insight into your kidney health since BUN levels can rise for other reasons, even when your kidney is healthy. Some of the reasons² include:

• Dehydration

• Aging

• High protein diet

• Steroid use

Measuring the ratio of BUN to creatinine is thus a more conclusive way of determining the health of your kidney. A ratio of between 10:1 and 20:1 is considered normal, while anything below or higher may point to kidney problems or dehydration.

Urine tests

The amount of urine sample required will depend on the type of test, with some requiring as little as two tablespoons while others need a collection of all the urine you have produced for 24 hours. The 24-hour test gives a better overview of kidney function. 

A urine test³ can be in the following forms.

Dipstick test

A dipstick is a chemically treated paper strip that changes color upon detecting abnormally high amounts of sugar, protein, bacteria, blood, or pus in your urine. The doctors can use an albumin-specific dipstick to determine the presence of protein such as albumin in your urine.

The presence of albumin in your urine points to an issue with your kidney since a healthy kidney wouldn't let albumin, typically found in the blood, pass into the urine.

An even more sensitive dipstick test can detect minute amounts of albumin in your urine. This test can be used where the standard dipstick turns negative. You are advised to take this test if you have diabetes or high blood pressure, as these conditions place you at risk of developing kidney disease.

Albumin to creatinine ratio (ACR)

In this test, healthcare professionals measure the amount of albumin and creatinine in your blood and then calculate the ratio by dividing the amount of urine albumin by the amount of creatinine in your urine. An outcome of 30 is within the normal range. ACR of 30–300 represents relatively high albumin levels, while ACR that exceeds 300 indicates excessive amounts of albumin, meaning that the kidney disease is at a severe stage.

Creatinine clearance

This test entails the collection of your urine for 24 hours. The urine sample is then tested for creatinine, after which doctors compute the amount of waste products your kidney filters out each minute. This test measures how well your kidney works and how much protein passes into your urine daily.

When should I go to the doctor?

You should visit a doctor if you present signs of kidney disease. These include:

• Fatigue

• Itchy skin

• Swelling in the arms or feet

• Muscle cramps

• Frequent or less frequent urination

These signs are nonspecific and may point to another disease. Therefore, it is prudent to visit a doctor as they will be able to diagnose the underlying condition.

You should also visit a doctor if you experience bleeding, a bladder infection, or a hernia following surgery for the transplant.

The anti-rejection medication given after a transplant may have serious side effects. You should thus visit your doctor if you experience high blood pressure, cataracts, diabetes, increased stomach acids, and bone disease, as these could be side effects.

Generally, you should see your doctor at least once annually for an evaluation of your single kidney and more often if you have been diagnosed with a kidney problem.

The lowdown

You may have one kidney for several reasons. It could be that you were born with a single kidney, underwent surgery to remove one of your kidneys, or decided to donate one. Either way, you can live a normal and healthy life with a single kidney. Still, it is advisable to take care of yourself by avoiding injury as damage through injury or disease could lead to kidney failure, forcing you to undergo dialysis or a kidney transplant.

You should also stick to a healthy diet and undergo regular evaluation, which can be carried out through blood and urine tests. Remember to visit a doctor if you experience symptoms of illness.