A nephrectomy, the procedure for removing a kidney, is major surgery performed to treat disease, such as cancer, or for organ donation. While immediate recovery is the focus, the long-term reality is living with a solitary kidney. Although a single kidney can sustain normal body functions, the remaining organ faces an increased workload. Understanding these long-term effects is important for maintaining optimal health and proactively managing potential risks years after the procedure.
How the Remaining Kidney Adapts
The body compensates for the loss of one kidney through a natural physiological response involving structural and functional adaptation. This adaptation begins almost immediately and involves two primary mechanisms: renal hypertrophy and hyperfiltration.
Renal hypertrophy is the physical increase in the size of the remaining kidney as its cells grow larger to handle the body’s filtration needs. Functionally, the kidney initiates hyperfiltration, where its individual filtering units, the nephrons, increase their workload and filtration rate. This allows the single kidney to achieve a total filtering capacity often around 70% to 80% of what two healthy kidneys provided.
This adaptive response is effective, allowing most individuals with a solitary kidney to live a normal life with stable function. The increased filtration rate efficiently clears waste products and excess fluid from the bloodstream. This compensatory mechanism ensures a single healthy kidney is capable of sustaining life without the need for dialysis.
Elevated Risk of Reduced Kidney Function
While the remaining kidney’s compensatory mechanisms are initially successful, the organ is subjected to a sustained, high-pressure workload. This prolonged hyperfiltration can eventually become maladaptive, increasing the risk of developing health issues compared to the general population. The sustained high pressure within the nephrons can lead to gradual damage over many years.
The most common long-term side effects are mild proteinuria and an increased incidence of hypertension. Proteinuria involves a higher-than-normal amount of protein leaking into the urine, which indicates stress or damage to the filtering structures. Individuals with a single kidney may also have a higher risk of developing new-onset high blood pressure years after the nephrectomy.
Hypertension is a concern because it can be caused by reduced kidney function and accelerate kidney damage, creating a cycle of decline. This chronic strain elevates the risk of developing Chronic Kidney Disease (CKD), typically defined as a sustained reduction in the estimated Glomerular Filtration Rate (eGFR) below 60 mL/min/1.73m². While the risk is elevated, only a small percentage of people progress to severe stages of CKD or end-stage kidney failure. Progression, if it occurs, is usually slow, often taking decades.
Long-Term Health Management and Monitoring
Proactive long-term management is the most effective way to mitigate the elevated risks associated with living with one kidney. Regular medical surveillance is a cornerstone of this strategy, allowing healthcare providers to detect subtle changes in function early. This typically involves annual or semi-annual checkups, including specific blood and urine tests.
Monitoring involves calculating the estimated Glomerular Filtration Rate (eGFR) via blood tests to assess filtering efficiency. Urine tests check for protein, specifically the albumin-to-creatinine ratio, which marks early kidney stress. Closely monitoring blood pressure is also a primary protective measure. Physicians recommend maintaining blood pressure within a healthy range, as aggressive control protects the single kidney from long-term vascular damage.
Lifestyle modifications play a large role in reducing the burden on the solitary kidney:
- Maintaining optimal hydration by drinking plenty of water throughout the day to support kidney function.
- Managing sodium intake, as excessive salt consumption can contribute to hypertension.
- Avoiding excessively high protein intake, which can increase the workload on the nephrons.
- Avoiding nonsteroidal anti-inflammatory drugs (NSAIDs) for pain relief, as these medications can temporarily reduce blood flow to the kidney.