Yes, it is possible to live a healthy life with only one kidney. The kidneys are bean-shaped organs that filter waste from the blood and remove it from the body through urine. Most people are born with two kidneys, but it is possible to live a normal lifespan with only one functioning kidney. This condition is called living with unilateral renal agenesis or having a single-kidney.
How do the kidneys work?
The kidneys perform several important functions in the body:
– Filter waste and excess fluid from the blood to be excreted from the body as urine. This process removes wastes like urea and maintains the right balance of water, salts and minerals in the body.
– Regulate blood pressure by producing renin, an enzyme that controls sodium levels.
– Stimulate red blood cell production by secreting erythropoietin.
– Activate vitamin D for bone health.
– Balance pH and electrolyte levels in the body.
Usually, these functions are shared between the two kidneys. Each kidney filters about 120-150 quarts of blood to produce 1-2 quarts of urine per day. Even with one kidney, these tasks can be accomplished at near-normal efficiency.
What causes a person to have one kidney?
There are two main reasons for having a single kidney:
– Congenital defect – Some babies are born with only one kidney due to abnormal development in the womb. This condition is called renal agenesis. It occurs in about 1 in 1000 births. The remaining kidney usually compensates and grows larger to take over the workload.
– Disease or injury – A person may lose or donate one kidney later in life due to disease, kidney cancer, injury, infection or other causes. The most common reason for kidney removal is renal cell carcinoma.
Other than congenital causes, the main reasons adults live with one kidney include:
– Kidney cancer – Removal of one kidney to stop cancer spreading.
– Kidney infection – Severe pyelonephritis may permanently damage one kidney.
– Kidney cysts – Polycystic kidneys may require removal.
– Kidney stones – Recurrent kidney stones may justify removing one kidney.
– Injury or trauma – Car accidents, sports injuries or Physical trauma can lead to kidney loss.
– Donation – Some healthy people donate one kidney to help someone who needs a transplant.
What happens when you have one kidney?
When a person has one kidney, the remaining kidney undergoes compensatory hypertrophy. This means it grows bigger to undertake the workload normally shared between two kidneys. The one kidney increases in size by 30-50% over several months. This allows it to adequately filter blood, remove waste and maintain fluid balance.
In most cases, kidney function in a single kidney is 80-85% of normal two-kidney function. Creatinine levels may be slightly higher, but overall health is often unaffected. Medications like ACE inhibitors or diuretics may need adjustment. But dialysis or kidney transplant is rarely required.
Pros of having one kidney
– No need for dialysis or transplant
– No major diet changes or fluid restrictions
– Can live a full and active life
– Kidney function often returns to 60-70% capacity
– Lower risk of some kidney diseases
– The single kidney gets bigger and stronger
Cons of having one kidney
– Higher risk of infection in remaining kidney
– Increased risk of kidney failure if other kidney is damaged
– Greater impact if kidney function declines
– Higher blood pressure and kidney strain
– Repeated urinary tract infections
– Dehydration and urinary tract blockages must be avoided
– Certain medications may need to be stopped or reduced
– Activities like contact sports may need to be limited
Is kidney function affected?
Kidney function is measured by the glomerular filtration rate (GFR). This estimates how much blood the kidneys filter per minute. A GFR over 90 is considered normal function.
In a single kidney, the GFR may initially drop to 30-40% after removal or donation. But over 6-12 months, the remaining kidney can recompensate up to 60-80% function. The GFR may stabilize around 70 mL/min long-term which is mild reduction in function.
This moderate decrease in GFR does not tend to cause problems in otherwise healthy adults. Dialysis is very rarely needed unless the single kidney is also affected by additional kidney disease, diabetes or high blood pressure. Children and younger adults generally have higher compensation from their single kidney.
Kidney function over time with one kidney
| Time since kidney removal | Average GFR |
|---|---|
| Initial after donation/removal | 30-40% |
| 2 weeks | 40-50% |
| 6 weeks | 50-60% |
| 3 months | 55-65% |
| 6 months | 60-70% |
| 12 months | 65-80% |
| Long term | 70% average |
Living kidney donor experience
Healthy adults can choose to donate one kidney to help someone who needs a transplant. This is known as living kidney donation. It allows people with kidney failure to avoid years of dialysis and prolongs life. The experience of donating a kidney is well-studied:
– Prior to donation, the donor undergoes extensive testing to ensure good health and kidney function.
– Laparoscopic keyhole surgery is used for a quicker recovery. Donors typically spend 1-2 days in hospital and 4-6 weeks recovering at home.
– Initial kidney function drops around 30-50% after donation but gradually improves.
– Most donors return to normal activity within 1-3 months. Strenuous sports may take longer.
– Lifelong risk of kidney failure is not increased after donation. Risk remains very low at 0.04% compared to 0.14% in non-donors.
– Overall life expectancy and quality of life are excellent with one kidney. Median survival over 15 years was similar for donors and matched controls.
– Kidney donors experience a profound sense of purpose and fulfillment from helping someone in need. Around 95% of donors say they would donate again.
Can you exercise with one kidney?
Yes, regular exercise is encouraged when you have one kidney. But there are some precautions to take:
– Start slow and build up endurance exercises like walking, swimming or cycling.
– Strength training is fine but avoid straining with extremely heavy weights.
– Stay well hydrated before, during and after physical activity.
– Avoid high-impact sports where a blow to the kidney area may occur – e.g. martial arts, rugby, hockey, boxing.
– Wear protective gear for remaining sports like soccer, volleyball, baseball.
– Stop exercise immediately if you feel pain in your kidney area and consult a doctor.
– Adjust intensity if you feel very fatigued and allow adequate rest periods.
– Supplementing with sodium and potassium may help compensate for losses in sweat.
Overall, light and moderate exercise provides cardiovascular, muscular and mental health benefits without overstraining the lone kidney. Just take care to avoid dehydration and direct kidney trauma.
Diet and lifestyle recommendations
People living with one kidney should follow a generally healthy diet and lifestyle. Recommendations include:
– Drink plenty of fluids daily – 2 to 3 liters is ideal. More when exercising and in hot weather.
– Avoid overuse of NSAIDs like ibuprofen which may strain the kidney. Use acetaminophen instead.
– Be vigilant with blood pressure control. Keep levels under 130/80 mmHg.
– Get labs done 1-2 times per year to check kidney function.
– Maintain a healthy weight as obesity strains the kidney.
– Limit protein intake to 0.8 – 1 gram per kg of bodyweight daily.
– Stop smoking and avoid secondhand smoke which is harmful to kidneys.
– Avoid taking supplements like creatine without medical advice.
Overall, those with a single kidney can eat a balanced diet low in sodium, saturated fat and refined sugars. Stay well hydrated, control blood pressure, and adopt a moderately active lifestyle.
Pregnancy concerns
Women with one kidney can often have normal pregnancies but may face a slightly higher risk of:
– Chronic kidney disease – baseline function is lower.
– Gestational hypertension – pregnancy raises pressures.
– Pre-eclampsia – blood pressure spikes.
– Preterm delivery – around 33% risk.
– Small for gestational age – 24% of babies.
– Low birth weight – average 300 grams less.
– Stillbirth – slightly higher rate at 1.1%
To protect the kidney and baby:
– Monitor kidney function and blood pressure closely.
– Take precautions to prevent UTI.
– Stay well hydrated and avoid NSAIDs.
– Deliver at 37-38 weeks if early pre-eclampsia.
Overall, those with a solitary kidney can successfully carry pregnancies in most cases. Work closely with your obstetrician and nephrologist. Share your medical history and monitor warning signs.
Living donor kidney transplant
For patients with end stage renal disease, a living donor transplant offers many benefits:
– Shorter wait times – No need to stay on the deceased donor list for years.
– Planned timing – Transplant can occur as soon as a willing donor is found.
– Better Match – Living donors are often genetically related.
– Kidney prepped optimally – Minimizes cold ischemia time.
– Lower risk of rejection – 5-7% with living donor, 15-20% deceased.
– Lasts longer – Average of 16 years vs 10 from deceased donor.
Almost any healthy person can donate a kidney. The most common living donors include:
– Blood relatives – Parents, siblings or children offer the best match.
– Spouses and partners – Emotional bond promotes donation.
– Friends or co-workers – Many Good Samaritans come forward.
Talk to family and share your need publicly to find a potential living donor. Paired exchange programs can facilitate swapped donations. Above all, never buy organs illegally. Living donation is always altruistic.
Prognosis and life expectancy
What is the life expectancy when you have one kidney? Several studies give insight:
– Young kidney donors – No increased long-term mortality risk observed even 40+ years later.
– Healthy elderly donors (over 70 years) – More than 75% 10-year survival rate if no comorbidities present.
– Kidney removal due to disease – Life expectancy depends on underlying condition. Cancer cured = normal lifespan.
– Solitary congenital kidney – Normal lifespan expected unless other urologic disorders develop.
– Chronic kidney disease develops – Life expectancy depends on progression rate and management. Dialysis may eventually be needed.
Overall, if the remaining kidney stays healthy, normal longevity can be expected. Monitor function yearly and control any co-existing conditions proactively.
Conclusion
Living with one kidney is well tolerated by most healthy adults. The remaining kidney adapts and takes on the extra workload. With some lifestyle precautions, kidney donors and those born with a single kidney can live a full life.
Monitor kidney function yearly. Stay well hydrated, control blood pressure, avoid nephrotoxins. While risks like infection and faster decline exist, prognosis is generally excellent.
A solitary kidney is not necessarily a barrier to healthy aging. Protect your kidney and it will keep working hard for you!