What happens to a person's body when one kidney is removed?

---

kidneyIt is a kind of human bodyorgan,belongUrinary systemPart of the bloodstream, it is responsible for filtering impurities from the blood, maintaining fluid and electrolyte balance, and finally producing urine which is excreted through subsequent ducts; it also has...endocrineadjustblood pressureIt stimulates the bone marrow to produce red blood cells. In normal adults...human bodyIt has two kidneys, located inwaistThe two square, bean-shaped structures located on either side of the lower back are about the size of a fist. Their main functions are to filter blood, remove excess water and metabolic waste (such as urea and creatinine), regulate electrolyte balance (such as sodium, potassium, and calcium), maintain stable blood pressure, and secrete important hormones (such as erythropoietin, EPO).

So, what changes occur in a person's body when they have to have a kidney removed for some reason, or choose to donate a kidney? This is a complex question involving physiology, medicine, and personal life.

1	renal pyramid		10	renal capsule (lower part)
2	Interlobar arteries		11	Kidney capsule (upper part)
3	Renal artery		12	Interlobular veins
4	renal vein		13	Kidney Essence
5	renal hilum		14	renal sinus
6	Renal pelvis		15	Renal calyx
7	ureter		16	renal nipple
8	renal calyx		17	Kidney column
9	Kidney sac

---

Basic understanding of the kidneys

project	Numerical value (adult)
Weight of each kidney	125–150 g
Whole renal blood flow	1.2 L/min
Number of nephrons	0.8–1.2 million/piece
Basic GFR*	90–120 mL/min/1.73 m²
Functional reserves	Approximately 75 %, resting and on standby.

---

Schematic diagram of a longitudinal section of a kidney (simplified).

┌──Adrenal gland│ ┌──Renal cortex (outer layer, main filtration)│ ├─Renal corpuscle│ └─Proximal convoluted tubule│ ├─Renal medulla (inner layer, concentrates urine)│ ├─Renal pyramids (8–18)│ └─Renal papillae│ └─Renal pelvis → ureter → bladder

---

Reason: Why is it necessary to remove a kidney?

The removal of a kidney is medically termed a nephrectomy, and the main reasons for this can be divided into two categories:Therapeutic and Donation.

Cause type	Specific details	illustrate
Therapeutic nephrectomy	Malignant tumor (kidney cancer)	The most common cause. In order to completely remove cancer cells and prevent their spread, the diseased kidney, along with some surrounding tissue, needs to be removed.
	Benign kidney disease	Such conditions include severe kidney stones with recurrent infections or loss of kidney function, obstructive hydronephrosis leading to severe kidney atrophy, intractable pain or complications caused by polycystic kidney disease, and uncontrollable kidney infections (such as purulent nephritis).
	trauma	A severe car accident, fall, or puncture injury can cause a kidney to rupture beyond repair, necessitating emergency surgery to remove it in order to save the patient's life.
	congenital abnormalities	In rare cases, the removal of an abnormally developed kidney (such as severe ureteropelvic junction obstruction) may be considered if it has extremely poor function and causes symptoms.
Donation nephrectomy	Living donor kidney transplantation	It is a noble act to voluntarily donate a healthy kidney to a relative or spouse who needs a transplant due to kidney failure (such as uremia).

---

The "advantages" and "disadvantages" of removing a kidney

The "advantages" and "disadvantages" here depend on the situation; they have completely different meanings for therapeutic resection and voluntary resection.

(a) Benefits

1. Treating disease and saving lives (in the context of therapeutic resection):
   • For patients with kidney cancer, removing the diseased kidney is the most important and effective way to cure the cancer, and its benefits far outweigh the risks of retaining a diseased kidney.
   • For patients suffering from long-term pain and discomfort due to infection, stones, or hydronephrosis, removing the diseased kidney that has lost its function and is the source of infection can eliminate pain, prevent serious complications such as systemic sepsis, and significantly improve their quality of life.
2. Giving new life to others (in the context of voluntary excision):
   • Although kidney donors endure surgical risks and physical changes, their actions free recipients from the suffering of lifelong dialysis, allowing them to regain health and a normal life. This brings immense psychological satisfaction and social value, representing unparalleled spiritual benefits.
3. Compensatory hyperplasia (for all individuals with a single kidney):
   • This isn't a "benefit" in the traditional sense, but rather a powerful adaptive mechanism of the body. The remaining healthy kidney senses the increased workload and improves overall function by increasing the size of the nephron (nephron function unit). This process is called...Compensatory hyperplasia(Compensatory Hypertrophy). Typically, within weeks to months after surgery, the filtration function of a single kidney can reach the combined function of both kidneys.70%-80%This is sufficient to meet daily physiological needs.

(ii) Disadvantages/Risks

In the long run, the biggest disadvantage for patients with a single kidney is the loss of renal reserve. Patients with two kidneys can utilize the reserve function of their other kidney when faced with stressful situations (such as severe infection, dehydration, or hypertension); however, the healthy kidney in a patient with a single kidney is already working at full capacity. If they encounter further kidney-damaging factors, they are more likely to experience a decline in kidney function. Specific potential risks are as follows:

1. Decreased renal reserve:
   • This is the core change. Although the remaining kidney function is sufficient to sustain life, the "reserve volume" is reduced. This means that people with only one kidney have a poorer compensatory capacity when faced with dehydration, infection, illness, or taking nephrotoxic drugs, making them more susceptible to acute kidney injury.
2. The risk of long-term chronic kidney disease (CKD) increases slightly.
   • Numerous long-term follow-up studies have shown that living kidney donors are more likely to develop certain diseases in the future.End-stage renal disease (ESRD) The absolute risk is very low (approximately 0.11 TP3T-0.51 TP3T), but compared to individuals with healthy kidneys, there is a statistically slight increase in risk. This may be related to the gradual sclerosis of the glomeruli and a slow decline in function after decades of hyperfiltration by the nephrons.
3. Increased risk of high blood pressure:
   • The kidneys are key organs for regulating blood pressure. Studies have found that individuals with only one kidney (especially kidney donors) are slightly more likely to develop hypertension in the future than their peers with two kidneys. This requires long-term monitoring and management.
4. Proteinuria:
   • Some individuals with a single kidney may experience mild proteinuria (protein in the urine), which is a common manifestation of increased glomerular filtration pressure and requires regular monitoring.
5. Risks of the surgery itself:
   • All major surgeries carry risks, including anesthesia allergies, bleeding, infection, poor wound healing, and blood clots. Although laparoscopic surgery, which is now mostly minimally invasive, has greatly reduced these risks, they cannot be completely eliminated.
6. Psychological impact:
   • Kidney donors, in particular, may experience anxiety about "I only have one kidney left," and become more sensitive or anxious about their bodies.

Weighing the pros and cons: For therapeutic resection, the criterion is "the trade-off between disease and life"; for voluntary resection, it is "the trade-off between altruism and self-harm". Under the rigorous evaluation and oversight of modern medicine, the decision in both cases usually outweighs the benefits.

---

Additional disadvantages for special populations

Older adults (age > 60 years)

Kidney function in the elderly already undergoes physiological decline (eGFR decreases by approximately 2 mL/min/1.73 m² per year). Removing another kidney may compromise the compensatory capacity of the healthy kidney, leading to a higher risk of postoperative kidney function decline. For example, one study showed that the proportion of patients over 60 years old with a single kidney whose kidney function declined to <60% five years post-surgery was 12%, three times higher than that of patients under 40 years old. Therefore, whether a single nephrectomy is suitable for an elderly patient requires a more rigorous evaluation by a physician.

child

Children's kidneys are still developing. If a kidney is removed due to a congenital malformation (such as nephroblastoma), the healthy kidney can maintain its function through "growth compensation" (increased kidney volume and increased number of nephrons). However, in the long run, the risk of hypertension and decreased kidney function is still higher than in adults. For example, the incidence of hypertension in adults is about 15% in children with a single kidney, requiring long-term monitoring of kidney function and blood pressure.

---

Time period: How does the body adapt over time?

The body's adaptation process after losing a kidney is a dynamic, phased journey.

Nursing focus: Infection prevention and avoiding increased abdominal pressure

• Postoperatively, the wound should be kept clean and kept dry to prevent infection (postoperative infection rate is approximately 21-31%).
• Avoid behaviors that increase abdominal pressure, such as violent coughing and constipation, to prevent abdominal wall incision from rupturing or perirenal hematoma from forming;
• The diet should be low in salt (daily salt intake <5g) and easily digestible to avoid increasing the burden on the kidneys.

1. Acute surgical phase (0-1 week post-surgery)

• Physical condition: The body is under stress from the surgical trauma. The function of the remaining kidney may temporarily and slightly decline due to factors such as anesthesia, pain, and changes in body fluids.
• Key Focus Areas: Managing pain, monitoring vital signs, ensuring unobstructed urination, and preventing surgical complications (such as bleeding and infection) are all important aspects of the procedure. Kidney function indicators (such as creatinine) will be closely monitored.

2. Compensatory proliferative phase (several weeks to 6 months post-surgery)

• Physical condition: This is due to the remaining kidney.Compensatory hyperplasiaThis is a crucial stage. The size of nephronocytes increases, and the overall filtration capacity of the kidneys significantly improves.
• Data changes: The glomerular filtration rate (eGFR) will rise rapidly from its postoperative low, typically after surgery.4-6 weeksThe total eGFR of both kidneys reached a new stable level, approximately 70-80 %, which was the preoperative total eGFR of both kidneys, and remained at this plateau for several months thereafter.
• Key Focus Areas: Regular blood and urine tests are necessary to monitor kidney function. Start establishing healthy lifestyle habits to protect your kidneys (drink plenty of water, eat a healthy diet).

3. Long-term stable period (more than 6 months after surgery)

• Physical condition: The vast majority of people with a single kidney will enter a period of stable function that lasts for decades. The remaining kidney has fully adapted to a single function.
• Key Focus Areas: Long-term, regular trackingThis is the core of this stage. A physical examination should be performed at least once a year, including blood pressure measurement, blood tests (creatinine, eGFR), and urine tests (proteinuria). The goal is to monitor for signs of high blood pressure, proteinuria, or a slow decline in kidney function and intervene promptly.

4. Old age (65 years and older)

• Physical condition: As people age, everyone's kidney function will naturally decline. People with only one kidney may experience a slightly steeper decline in kidney function than their peers because they already have less kidney reserve, but this does not mean they will necessarily need dialysis.
• Key Focus Areas: It is even more necessary to strictly control blood pressure, blood sugar, and blood lipids, avoid the use of kidney-damaging drugs such as non-steroidal anti-inflammatory drugs (NSAIDs), and work closely with doctors to manage health.

Changes in renal function indicators (mean values) 1-6 months post-operatively in patients who underwent single nephrectomy

Time point	Serum creatinine (mg/dL)	Glomerular filtration rate (eGFR, mL/min/1.73m²)	Urine output (mL/day)
Preoperative (both kidneys)	0.85±0.12	105±15	1800±300
One month after surgery	1.32±0.18	68±10	1600±250
3 months post-surgery	1.25±0.15	72±9	1700±200
6 months post-surgery	1.18±0.13	75±8	1750±200

---

Data and Charts: Long-Term Impacts from a Research Perspective

The following chart summarizes multiple aspects of...Living kidney donorsLong-term follow-up data (for the healthiest single-kidney population) can most purely reflect the impact of removing a healthy kidney.

Chart 1: Change in glomerular filtration rate (eGFR) over time
This chart shows the typical trajectory of eGFR changes before and after kidney donation.

 eGFR (mL/min/1.73m²) ^ | /----------------------\ (Single kidney stable plateau) 120| / \ | / \ 100| / \ | / \ 80 | - - - - - - - - - - - / - - - - - - - - - - - - - - - - - - - - (Bilateral kidney baseline) | / 60 | / | / 40 | / | / 20 | / |_____________|_______________________________________> Time Preoperative Surgery 6 months 10+ years Acute phase

• illustrate: Preoperatively, the eGFR of both kidneys was approximately 100. During the acute postoperative period, the pressure decreased slightly, followed by compensatory hyperplasia, which caused the eGFR to rise rapidly and stabilize at a level of 70-80, which was maintained long-term.

Chart 2: Cumulative incidence of end-stage renal disease (ESRD) in individuals with a single kidney and healthy controls.
This chart compares the risk of two groups eventually needing dialysis or transplantation.

Cumulative incidence (%) ^ | 1.5 | ***************** | * * 1.0 | * * | * * 0.5 | * * - - - - - - - - - - - - - - - - - (Control group) | * * 0.0 |____*_______________*___________________________________> Age 40 years 70 years

• Data Interpretation: Although the magnified graph shows a higher risk in the kidney donor group (* line) compared to the control group (dashed line), note the extremely small scale of the Y-axis (0.%-1.5%). This means the difference in absolute risk is very small. Most studies show that the lifetime risk of ESRD in kidney donors is only about 0.5%-1%, while the risk in the general population is about 0.2%-0.3%.

Chart 3: Comparison of the incidence of hypertension between individuals with a single kidney and the control group
(Taking the 60-year-old age group as an example)

Incidence (%) ^ | 60 | ************* | * 50 | * ************* | * * 40 | * * ----------(Control Group) | * * 30 | * * |__________________________*___________> Group Single Kidney Group Control Group

• Data Interpretation: Multiple studies have confirmed that individuals with only one kidney are more likely to develop hypertension as they age than healthy controls with both kidneys. Therefore, it is crucial to focus on blood pressure management from a young age.

---

Kidney function and health status of living kidney donors 1 year, 5 years and 10 years after surgery

Time point	Serum creatinine (mg/dL)	eGFR (mL/min/1.73m²)	Incidence of hypertension (%)	Incidence of proteinuria (%)	The proportion of patients with renal function declining to <60 (%)
1 year after surgery	1.15±0.14	76±9	5.2	1.8	2.1
5 years after surgery	1.18±0.15	74±10	7.5	2.3	3.5
10 years after surgery	1.22±0.16	72±11	9.8	2.8	4.8

The study also investigated the quality of life of the donors. The results showed that 10 years after the surgery, the 89% donors reported that "there was no significant difference in their lives compared to before the kidney donation." They were able to work normally, exercise (such as running and swimming), and have children. Only the 11% patients felt that their quality of life had declined due to "concerns about kidney function," but this was not caused by physiological damage.

Furthermore, long-term data for patients undergoing therapeutic resection are similar to those for donors. For example, a 5-year follow-up study of patients who underwent early-stage renal resection showed that patients with 85% had stable renal function, no cancer recurrence, and no significant difference in quality of life compared to healthy individuals 5 years post-surgery.

---

Life advice

Removing a kidney is not the end of the world, but a turning point in life. The body has an amazing compensatory ability, allowing a single kidney to handle most of the work. However, this also means that you must cherish and care for this "silent treasure" even more than someone with two kidneys.

Lifestyle guidelines for people with a single kidney:

1. Regular monitoring is essential; never neglect it. It is an ironclad rule to have your kidney function checked at least once a year (blood pressure, blood test, urine test).
2. Drink plenty of water and never dehydrate: Drink enough water every day (about 2000cc, adjust according to individual circumstances) to help the kidneys excrete waste.
3. Healthy eating, less burden: Maintain a balanced diet, avoiding excessive salt and oil. Unless instructed by a doctor, an extremely low-protein diet is not necessary, but high-protein intake (such as large amounts of protein powder) should be avoided to prevent increasing the burden on the kidneys.
4. Use medication with caution to protect your kidneys: Never take any medications, herbal remedies, or folk remedies of unknown origin without consulting a doctor. When you see a doctor, be sure to tell them that you only have one kidney and ask them to avoid prescribing nephrotoxic drugs (such as nonsteroidal anti-inflammatory drugs (NSAIDs) and certain antibiotics).
5. Controlling the three highs (high blood pressure, high blood sugar, and high cholesterol) and protecting the kidneys at their source: Strictly controlling blood pressure, blood sugar, and blood lipids is the most important way to protect residual kidney function.
6. Maintain a healthy weight: Avoid obesity to reduce the filtering burden on your kidneys.
7. Moderate exercise, avoid extremes: Regular exercise is encouraged, but extreme sports that can easily lead to dehydration or severe impacts (such as professional boxing and ultramarathons) should be avoided.

---

Long-term screening plan for patients with a single kidney

Inspection items	1-6 months post-surgery	6 months to 1 year post-surgery	More than 1 year after surgery	Principles for handling exceptions
Complete blood count (for anemia)	Every 1-2 months	Every 3 months	Every 6 months	If anemia is present (hemoglobin <120g/L), rule out renal anemia. If necessary, supplement with iron or erythropoietin.
Blood biochemistry (creatinine, blood urea nitrogen)	Every 1-2 months	Every 3 months	Every 6 months	If creatinine levels are elevated >20%, investigate the cause of kidney damage (such as medication or infection) and adjust lifestyle accordingly.
eGFR (glomerular filtration rate)	Every 2 months	Every 3 months	Every 6 months	If eGFR < 60, a consultation with a nephrologist is necessary to develop a kidney function protection plan.
Urinalysis (checks for protein and occult blood)	Every 2 months	Every 3 months	Every 6 months	If urine protein is positive, further 24-hour urine protein quantification should be performed, and medication may be necessary to control it.
Blood pressure measurement	Every month	Every 1-2 months	Every 3 months	If blood pressure is >140/90 mmHg, consult a doctor to adjust antihypertensive medication.
Kidney ultrasound (to check kidney size and stones)	3 months post-surgery	6 months post-surgery	Once a year	If a stone larger than 0.5cm is found, medical treatment is necessary to prevent obstruction.

Medication management: Avoid nephrotoxic drugs

In patients with only one kidney, the healthy kidney's ability to metabolize and excrete drugs is reduced, nephrotoxic drugs must be strictly avoided. A doctor must be consulted before medication, and the patient's "single kidney status" must be disclosed. Common nephrotoxic drugs include:

• Nonsteroidal anti-inflammatory drugsDrugs such as ibuprofen, aspirin (long-term use in large doses), and naproxen may cause renal ischemia and renal tubular damage.
• Some antibioticsDrugs such as gentamicin, amikacin (aminoglycoside), and amphotericin B should be used under the guidance of a doctor, and kidney function should be monitored.
• Contrast agentsFor example, iodine contrast agents used in CT enhanced scans may cause "contrast nephropathy." Adequate fluid intake is necessary before use, and preventative medication may be required.
• Chinese herbal medicineProducts such as Aristolochia manshuriensis and Stephania tetrandra (containing aristolochic acid) have been proven to be nephrotoxic and must be absolutely avoided.

---

Clarifying Common Misconceptions—The "Can" and "Cannot" of Patients with a Single Kidney

There are many misconceptions about patients with a single kidney, such as "a single kidney means you can't get married and have children" or "a single kidney means you can't exercise." These misconceptions not only affect the patient's mental state but may also lead to overprotection or neglect of management. Here are some clarifications of common misconceptions:

Misconception 1: Men with only one kidney cannot get married and have children.

factMost patients with a single kidney have the same reproductive function as those with two kidneys and can marry and have children normally.

• male patientsA single kidney does not affect sperm production and quality. Studies show that the sperm motility and quantity of kidney donors after the procedure are not significantly different from those before donation, and their partners can conceive normally.
• female patientsThe burden on the kidneys increases during pregnancy, but patients with a single kidney who have normal kidney function before surgery and undergo strict monitoring during pregnancy (checking kidney function and blood pressure every 1-2 months) can usually have a successful pregnancy and delivery. For example, a study on women who donated kidneys showed that the success rate of pregnancy after surgery was 92%, and the premature birth rate was no different from that of ordinary pregnant women. They only needed to avoid high-salt diets and strenuous exercise during pregnancy.

Misconception 2: Patients with a single kidney cannot exercise and can only "rest" (i.e., be physically rested).

factPatients with a single kidney can gradually resume exercise 6 months after surgery; moderate exercise is beneficial to health.
Excessive restriction of exercise can lead to decreased physical strength and obesity, which in turn increases the risk of high blood pressure and diabetes, and is detrimental to kidney function protection. Patients with a single kidney can choose moderate-intensity aerobic exercises, such as brisk walking, swimming, and yoga, which can not only improve physical fitness but also improve vascular function and help control blood pressure. They only need to avoid "intense impact sports" (such as boxing and rugby) and "overload sports" (such as marathons) to prevent kidney damage.

Misconception 3: Patients with a single kidney will eventually experience kidney failure and require dialysis.

factMost patients with a single kidney will not develop kidney failure; only a small number of patients with serious underlying diseases are at risk.
As shown in Chapter 3, 10 years post-surgery, only 4.81 TP3T of patients with a single kidney experienced mild renal impairment (eGFR < 60), and the proportion progressing to end-stage renal disease (requiring dialysis or transplantation) was only 0.51 TP3T, far lower than the incidence of renal failure in the general population (approximately 11 TP3T). With long-term adherence to scientific management (low-salt diet, regular check-ups, and avoidance of nephrotoxic factors), most patients with a single kidney can maintain normal renal function for life without the need for dialysis.

Misconception 4: Patients with a single kidney need to "nourish their kidneys" and take more health supplements.

factThere is currently no scientific evidence to prove that "health supplements can nourish the kidneys." On the contrary, some health supplements contain nephrotoxic ingredients that may damage healthy kidneys.
Patients with a single kidney typically have normal kidney function and do not require additional supplementation. They only need to ensure adequate nutrition through a balanced diet (such as moderate intake of fish, eggs, and dairy products) and avoid taking health supplements with unknown ingredients (such as "Shenbao" or "Bu Shen Wan"). If there is a nutritional deficiency (such as iron or vitamin D deficiency), supplementation should be done under the guidance of a doctor, rather than relying on health supplements.

---

Conclusion – Having a single kidney is not a "disability"; scientific management is key.

Removing a kidney is a "major adjustment" for the body, but not a "disaster." In the short term, the body will experience trauma recovery and short-term fluctuations in kidney function 1-4 weeks after surgery, but most can get through this smoothly. In the long term, patients with a single kidney and a TP3T of 851 or higher can maintain normal kidney function for life, and their quality of life is no different from those with two kidneys.

The so-called "disadvantages" are mostly "potential risks" rather than "inevitable consequences," and can be avoided through scientific management: a low-salt diet can prevent high blood pressure, regular checkups can detect problems early, and nephrotoxic drugs can be avoided to protect healthy kidneys. Instead of worrying about "what will happen if I lose a kidney," it's better to learn "how to manage the remaining kidney."

Finally, whether you are a patient who has had a kidney removed due to illness or a volunteer who selflessly donates a kidney, you should all realize that having only one kidney is not a "disability," but a "special state of health." As long as you adhere to scientific management, you can work, live, and enjoy life just like a normal person.

In conclusion, you can still live a fulfilling, healthy, and long life even after losing a kidney. The key to success lies in "awareness" and "action": recognizing the changes in your body and taking proactive steps to embrace a healthy life with only one kidney.

Further reading:

• Why is urine light yellow?
• What is the pancreas? What is its function?
• The profound impact of diabetes on male sexual function
• What is male semen?