Solitary kidney

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at December 4, 2016
StartDiseasesSolitary kidney

Solitary kidney is a condition in which a person has only one normal and functioning kidney instead of two. While it is possible to survive and live a full life with this condition, there are complications a person should be aware of.


Definition & Facts

The kidneys are vital organs responsible for filtering waste from the blood. The kidneys also help to regulate blood pressure and balance the mineral concentrations in the bloodstream.

A healthy person has two kidneys. This is important because the kidneys are not as robust or as regenerative as the body’s other filtration organ, the liver. In most cases, kidney disease or kidney damage is untreatable or irreversible. While a person can survive with only one kidney, kidney failure will result in the need for lifelong dialysis or kidney transplant.

Symptoms & Complaints

Most people will not notice any difference in their health or daily living with a solitary kidney. As long as this remaining kidney is functioning correctly, it can handle the job of filtering the blood just as well as having both kidneys. However, there is a greater risk of serious complications with only one kidney.

If these complications arise, or if the remaining kidney begins to fail, serious health conditions can happen quickly. The most common complications are increased protein in the urine and reduced blood filtration rate.

As long as these conditions are monitored and managed correctly, they rarely interfere in daily life. Minor problems with blood pressure are also a common symptom of solitary kidney. The increased strain on the remaining kidney makes it more likely to suffer from early kidney disease or kidney failure, which can be life-threatening if left untreated.


A solitary kidney may happen naturally as part of a birth defect. It may also occur due to surgical removal of a kidney. There are many reasons a kidney may be removed. If the kidney becomes diseased, injured or infected, removing it may be the best course of action. Cancer is a leading cause of kidney removal.

There are many possible causes of kidney damage that may prompt removal of the kidney. A common cause is a kidney stone that can irreparably break the tiny blood vessels inside the kidney, leading to excessive and dangerous internal bleeding.

Kidney damage may also result from a surgical mistake near a kidney. Additionally, a person may choose to donate one of the kidneys to a needy friend or family member experiencing kidney failure.

Kidney disease is generally progressive and eventually the kidneys begin to fail. If this occurs, and the person is left with only one functioning kidney, they will be considered to have a solitary kidney condition. The nonfunctional kidney may or may not be surgically removed depending the health risk it poses.

Diagnosis & Tests

Depending on the cause of the solitary kidney, a diagnostic testing may or may not be necessary. Diagnosis is most often needed when the solitary kidney is due to a birth defect. People in this situation often discover that they have a solitary kidney by accident while being examined for another condition.

X-rays and ultrasounds are the most common diagnostic methods for identifying a single kidney condition. Beyond diagnosis, a person that has a single kidney condition will need routine monitoring to ensure the health of the kidney and identify complications before they become serious.

A person will undergo several distinct tests including albuminuria testing, GFR testing (glomerular filtration rate testing), and high blood pressure monitoring. Albuminuria can be tested with a simple dipstick test on a urine sample. GFR testing requires a blood sample. Blood pressure monitoring is routine.

Treatment & Therapy

Those that have a solitary kidney can make a variety of lifestyle changes that will help keep their remaining kidney in good condition for the remainder of their lives. Controlling blood pressure is one of the most important treatments. This can be done in many ways such as reducing stress or taking antihypertensive drug.

A person will also want to avoid eating an excessive amount of protein because this will strain the kidneys. Excessive sodium intake is a common cause of kidney stones, so one may be recommended to adopt a low-sodium diet. It is important to protect the remaining kidney from injury that could reduce its functioning or damage it irreversibly. This may mean avoiding aggressive contact sports and taking special care to avoid slip and fall injuries.

Certain medications and medical procedures can also strain the kidneys or risk damaging them. It is important to explain a solitary kidney condition to a doctor and avoid taking medications that are processed through the kidneys.

For example, many painkillers are processed through the kidneys, but there are alternatives that are processed through the liver instead. It is also a good idea to avoid certain long-term medications and excessive use of nonsteroidal anti-inflammatory drugs (NSAID) such as ibuprofen as they can cause analgesic nephropathy.

Prevention & Prophylaxis

It is not always possible to prevent a single kidney condition because many people are born with it. The best way to avoid the condition otherwise is to keep a healthy lifestyle that promotes kidney health and function, does not strain the kidneys, and does not risk damaging or injuring them.

Diet is one of the most powerful tools for health and disease prevention. A healthy diet that increases the intake of fruits and vegetables and limits excessive intake of protein and sodium will benefit kidney function. Drinking plenty of water and avoiding dehydration also benefits kidney function and overall health.

Diabetes is one of the leading risk factors for kidney disease and failure. If a person has diabetes, they will need to take extra precautions to ensure they do not also develop kidney disease. This means keeping very good control of blood glucose levels, avoiding cigarettes or quitting smoking, and controlling blood pressure.