ICD-10: N18.4

Chronic Kidney Disease (CKD) is a progressive condition characterized by a gradual loss of kidney function over time. The ICD-10 code N18.4 specifically refers to Chronic Kidney Disease, Stage 4 (Severe), which indicates a significant decline in kidney function and necessitates careful management and monitoring.

Clinical Description of N18.4

Definition and Classification

Chronic Kidney Disease is classified into five stages based on the glomerular filtration rate (GFR), which measures how well the kidneys filter blood. Stage 4 is defined by a GFR of 15 to 29 mL/min, indicating severe impairment of kidney function. At this stage, patients are at high risk for complications, including cardiovascular disease, anemia, and bone disease, and may require preparation for renal replacement therapy, such as dialysis or kidney transplantation[1][2].

Symptoms and Clinical Manifestations

Patients with Stage 4 CKD may experience a range of symptoms, including:

• Fatigue and weakness: Due to anemia and the accumulation of waste products in the blood.
• Swelling (edema): Particularly in the legs, ankles, and around the eyes, due to fluid retention.
• Changes in urination: This may include decreased urine output or changes in urine color.
• Nausea and vomiting: Resulting from the buildup of toxins in the body.
• Itching (pruritus): Often due to the accumulation of waste products.
• Shortness of breath: This can occur due to fluid overload or anemia[3][4].

Diagnostic Criteria

Diagnosis of CKD Stage 4 involves:

• Laboratory Tests: Measurement of serum creatinine and calculation of GFR using formulas such as the MDRD or CKD-EPI equations.
• Urinalysis: To check for proteinuria, hematuria, or other abnormalities.
• Imaging Studies: Ultrasound or CT scans may be used to assess kidney size and structure.
• Assessment of Comorbidities: Evaluating for conditions such as diabetes and hypertension, which are common in CKD patients[5][6].

Management and Treatment

Management of CKD Stage 4 focuses on slowing disease progression and managing complications:

• Medication Management: This may include antihypertensives, erythropoiesis-stimulating agents (ESAs) for anemia, and phosphate binders for mineral and bone disorder.
• Dietary Modifications: A renal diet may be recommended, which typically includes restrictions on protein, sodium, potassium, and phosphorus intake.
• Monitoring: Regular follow-up appointments to monitor kidney function, electrolytes, and overall health status.
• Preparation for Renal Replacement Therapy: Discussions regarding dialysis options or kidney transplantation should begin at this stage, as patients may progress to end-stage renal disease (ESRD) if kidney function continues to decline[7][8].

Conclusion

ICD-10 code N18.4 represents a critical stage in the management of Chronic Kidney Disease, where proactive measures are essential to prevent further deterioration of kidney function and to address the myriad of complications associated with severe CKD. Early intervention and comprehensive care can significantly improve patient outcomes and quality of life. Regular monitoring and a multidisciplinary approach involving nephrologists, dietitians, and primary care providers are vital in managing patients with this condition effectively.

References

1. Chronic Kidney Disease - CKD[1].
2. ICD-10 Code for Chronic kidney disease, stage 4 (severe)[2].
3. Documentation and Coding Chronic Kidney Disease[3].
4. Billing and Coding: Erythropoiesis Stimulating Agents (ESAs)[4].
5. Chronic Kidney Disease (Category N18)[5].
6. ICD-10 Version:2019[6].
7. Article - Billing and Coding: Heavy Metal Testing (A56767)[7].
8. 2025 ICD-10-CM Diagnosis Code N18.4[8].

Chronic kidney disease (CKD) stage 4, classified under ICD-10 code N18.4, represents a critical phase of kidney dysfunction characterized by a significant decline in renal function. Understanding the clinical presentation, signs, symptoms, and patient characteristics associated with this condition is essential for effective diagnosis and management.

Clinical Presentation

Definition and Overview

Chronic kidney disease stage 4 is defined by a glomerular filtration rate (GFR) of 15 to 29 mL/min, indicating severe impairment of kidney function. At this stage, patients are at high risk for complications, including cardiovascular disease, anemia, and bone mineral disorders, necessitating careful monitoring and potential preparation for renal replacement therapy, such as dialysis or kidney transplantation[1].

Signs and Symptoms

Patients with CKD stage 4 may exhibit a range of signs and symptoms, which can vary in severity. Common manifestations include:

• Fatigue and Weakness: Due to anemia and the accumulation of waste products in the blood, patients often report significant fatigue and a general sense of weakness[2].
• Edema: Fluid retention can lead to swelling in the legs, ankles, and around the eyes, as the kidneys struggle to excrete excess fluid[3].
• Hypertension: High blood pressure is prevalent in CKD patients, often exacerbated by fluid overload and hormonal imbalances[4].
• Changes in Urination: Patients may experience changes in urinary patterns, including decreased urine output or nocturia (increased urination at night)[5].
• Nausea and Vomiting: Accumulation of toxins can lead to gastrointestinal symptoms, including nausea, vomiting, and loss of appetite[6].
• Itching (Pruritus): Uremic pruritus is common, resulting from the buildup of waste products in the bloodstream[7].
• Bone Pain: Mineral and bone disorders can lead to bone pain and increased risk of fractures due to altered calcium and phosphate metabolism[8].

Patient Characteristics

Certain demographic and clinical characteristics are commonly observed in patients with CKD stage 4:

• Age: CKD is more prevalent in older adults, with the risk increasing significantly after age 60[9].
• Comorbidities: Many patients have comorbid conditions such as diabetes mellitus and hypertension, which are leading causes of CKD[10].
• Ethnicity: Certain ethnic groups, including African Americans and Hispanics, are at higher risk for developing CKD due to genetic and socioeconomic factors[11].
• Gender: There is a slight male predominance in CKD prevalence, although women may experience more severe symptoms[12].
• Lifestyle Factors: Obesity, smoking, and sedentary lifestyle are significant risk factors that can exacerbate kidney disease progression[13].

Conclusion

Chronic kidney disease stage 4 (ICD-10 code N18.4) is a severe condition that requires comprehensive management due to its complex clinical presentation and associated symptoms. Recognizing the signs and understanding patient characteristics can aid healthcare providers in delivering appropriate care and interventions. Early identification and management of complications are crucial to improving patient outcomes and quality of life. Regular monitoring and a multidisciplinary approach are essential in managing this advanced stage of kidney disease effectively.

Chronic Kidney Disease (CKD) is classified into different stages based on the severity of kidney damage and the level of kidney function. The ICD-10 code N18.4 specifically refers to Chronic Kidney Disease, Stage 4 (severe). This classification is crucial for healthcare providers for diagnosis, treatment planning, and billing purposes. Below are alternative names and related terms associated with ICD-10 code N18.4.

Alternative Names for N18.4

1. Severe Chronic Kidney Disease: This term emphasizes the severity of the condition, indicating significant impairment of kidney function.
2. Stage 4 CKD: A straightforward reference to the specific stage of chronic kidney disease, often used in clinical settings.
3. End-Stage Renal Disease (ESRD): While technically referring to Stage 5, some may colloquially use this term when discussing advanced stages of CKD, including Stage 4, due to the high risk of progression to ESRD.
4. Advanced Chronic Kidney Disease: This term highlights the progression of the disease and the need for more intensive management.
5. Severe Renal Insufficiency: This term is sometimes used interchangeably with severe CKD, focusing on the kidneys' inability to function adequately.

Related Terms

1. Chronic Kidney Disease (CKD): The broader category that includes all stages of kidney disease, from Stage 1 to Stage 5.
2. Renal Failure: A general term that can refer to both acute and chronic conditions where the kidneys fail to filter waste effectively.
3. Kidney Dysfunction: A term that encompasses various degrees of kidney impairment, including CKD.
4. Nephropathy: A general term for kidney disease, which can include diabetic nephropathy, hypertensive nephropathy, and others that may lead to CKD.
5. Erythropoiesis-Stimulating Agents (ESAs): Medications often used in patients with CKD to manage anemia, which is a common complication of severe kidney disease.

Clinical Context

Understanding these alternative names and related terms is essential for healthcare professionals involved in the management of patients with CKD. Accurate coding and terminology ensure proper treatment protocols and facilitate communication among healthcare providers. Additionally, awareness of these terms can aid in patient education, helping individuals understand their condition and the importance of monitoring and managing their kidney health.

In summary, ICD-10 code N18.4 encompasses various terminologies that reflect the severity and implications of chronic kidney disease at this advanced stage. Recognizing these terms can enhance clarity in clinical discussions and documentation.

Chronic Kidney Disease (CKD) stage 4, classified under ICD-10 code N18.4, represents a critical phase of kidney dysfunction where the glomerular filtration rate (GFR) is significantly reduced, typically between 15 to 29 mL/min. At this stage, patients are at a high risk for complications, and management strategies focus on slowing disease progression, managing symptoms, and preparing for potential renal replacement therapy. Below, we explore standard treatment approaches for CKD stage 4.

1. Medical Management

a. Blood Pressure Control

Maintaining optimal blood pressure is crucial in CKD management. The target is usually less than 130/80 mmHg. Angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) are commonly prescribed, as they not only control hypertension but also provide renal protective effects by reducing proteinuria[1][2].

b. Diabetes Management

For patients with diabetes, strict glycemic control is essential. This may involve the use of medications such as metformin, SGLT2 inhibitors, or GLP-1 receptor agonists, which have shown benefits in reducing cardiovascular risks and slowing CKD progression[3][4].

c. Lipid Management

Statins are often recommended to manage dyslipidemia, as they can help reduce cardiovascular risks associated with CKD[5]. Regular monitoring of lipid levels is important to adjust therapy as needed.

d. Anemia Management

Anemia is common in CKD stage 4 due to decreased erythropoietin production. Erythropoiesis-stimulating agents (ESAs) and iron supplementation may be used to manage anemia, aiming to maintain hemoglobin levels within a target range[6][7].

e. Bone and Mineral Disorder Management

Patients with CKD often experience disturbances in calcium and phosphate metabolism, leading to bone disease. Phosphate binders, vitamin D analogs, and calcimimetics may be prescribed to manage these abnormalities and prevent complications such as secondary hyperparathyroidism[8][9].

2. Dietary Modifications

a. Protein Restriction

A moderate protein restriction (0.6 to 0.8 g/kg/day) may be recommended to reduce the burden on the kidneys while ensuring adequate nutrition. This approach can help slow the progression of kidney disease[10][11].

b. Sodium and Fluid Management

Limiting sodium intake is important to control blood pressure and reduce fluid retention. Patients may also need to monitor fluid intake to prevent overload, especially if they develop symptoms of heart failure or edema[12].

c. Potassium and Phosphorus Control

Monitoring and managing potassium and phosphorus levels is critical, as hyperkalemia and hyperphosphatemia can occur in advanced CKD. Dietary adjustments may be necessary to avoid high-potassium and high-phosphorus foods[13].

3. Preparation for Renal Replacement Therapy

As CKD progresses, discussions regarding renal replacement therapy (RRT) options, including dialysis and kidney transplantation, become essential. Patients should be educated about the different modalities of dialysis (hemodialysis vs. peritoneal dialysis) and the process of transplantation, including the evaluation for potential living or deceased donor options[14][15].

4. Monitoring and Follow-Up

Regular follow-up appointments are crucial for monitoring kidney function, managing complications, and adjusting treatment plans as necessary. This includes routine blood tests to assess GFR, electrolytes, hemoglobin levels, and other relevant parameters[16].

Conclusion

The management of CKD stage 4 (ICD-10 code N18.4) requires a comprehensive and multidisciplinary approach aimed at slowing disease progression, managing complications, and preparing for potential renal replacement therapy. By implementing effective medical management, dietary modifications, and regular monitoring, healthcare providers can significantly improve patient outcomes and quality of life. Continuous education and support for patients and their families are also vital components of effective CKD management.

References

1. ICD-10 2018 Coding Guidelines for Chronic Kidney Disease.
2. Chronic Kidney Diseases.
3. Managing comorbidities in chronic kidney disease reduces complications.
4. Contemporary in-hospital and long-term prognosis of CKD.
5. ICD-10 Codes to Report Kidney-related Illnesses.
6. Draft CKD Care Plan Data Elements.
7. Canadian Coding Standards for Version 2018 ICD-10-CA.
8. 2025 ICD-10-CM Diagnosis Code N18.4.
9. ICD-10-CM Official Guidelines for Coding and Reporting.
10. FY2022 April1 update ICD-10-CM Guidelines.
11. Chronic Kidney Disease - CKD - HIA Code.
12. ICD-10-CM Code N18.4 Chronic kidney disease, stage 4 (severe).
13. 2025 ICD-10-CM Codes N18*: Chronic kidney disease (CKD).
14. ICD-10-CM code "N18.4": Chronic kidney disease, stage 4 (severe) (2024).
15. Managing comorbidities in chronic kidney disease reduces complications.
16. Contemporary in-hospital and long-term prognosis of CKD.

Chronic Kidney Disease (CKD) is classified into stages based on the severity of kidney damage and the level of kidney function, measured by the glomerular filtration rate (GFR). The ICD-10 code N18.4 specifically refers to Chronic Kidney Disease, Stage 4 (severe). Here’s a detailed overview of the criteria used for diagnosing this condition.

Diagnostic Criteria for Chronic Kidney Disease, Stage 4 (N18.4)

1. Glomerular Filtration Rate (GFR)

The primary criterion for diagnosing CKD stage 4 is a significantly reduced GFR. For stage 4 CKD, the GFR is typically between 15 and 29 mL/min/1.73 m². This measurement indicates severe kidney impairment, where the kidneys are functioning at less than 30% of their normal capacity[1].

2. Kidney Damage Indicators

In addition to GFR, the diagnosis of CKD stage 4 may involve evidence of kidney damage, which can be assessed through various means:
- Proteinuria: The presence of excess protein in the urine, often measured by a urine protein-to-creatinine ratio.
- Hematuria: The presence of blood in the urine, which can indicate underlying kidney damage.
- Structural abnormalities: Imaging studies (such as ultrasound or CT scans) may reveal structural changes in the kidneys, such as cysts, stones, or scarring[2].

3. Duration of Kidney Dysfunction

To classify a patient as having CKD, the kidney dysfunction must be present for three months or longer. This chronicity is essential for the diagnosis, distinguishing CKD from acute kidney injury (AKI) which may present with similar symptoms but is typically reversible[3].

4. Clinical Symptoms

While many patients with stage 4 CKD may be asymptomatic, some may exhibit symptoms related to kidney failure, including:
- Fatigue
- Swelling (edema) due to fluid retention
- Changes in urination patterns (e.g., increased frequency or decreased output)
- Nausea or vomiting
- Itching (pruritus) due to the accumulation of waste products in the blood[4].

5. Laboratory Tests

Routine laboratory tests are crucial in diagnosing and monitoring CKD. These tests may include:
- Serum creatinine: Elevated levels indicate reduced kidney function.
- Electrolyte levels: Imbalances in potassium, sodium, and phosphate can occur as kidney function declines.
- Complete blood count (CBC): Anemia is common in CKD due to decreased erythropoietin production by the kidneys[5].

6. Comorbid Conditions

Patients with CKD stage 4 often have comorbid conditions such as hypertension and diabetes, which can exacerbate kidney damage. The management of these conditions is critical in the overall treatment plan for CKD[6].

Conclusion

The diagnosis of Chronic Kidney Disease, Stage 4 (ICD-10 code N18.4) relies on a combination of GFR measurements, evidence of kidney damage, the duration of kidney dysfunction, clinical symptoms, and laboratory tests. Early diagnosis and management are essential to slow the progression of the disease and mitigate complications associated with severe kidney impairment. Regular monitoring and a comprehensive treatment approach can significantly improve patient outcomes and quality of life.

References

1. Chronic Kidney Disease (Category N18) [1].
2. Documenting and Coding Tips: Chronic kidney disease [5].
3. How to Classify CKD [10].
4. Chronic Kidney Disease - CKD [9].
5. Billing and Coding: Erythropoiesis Stimulating Agents (ESAs) [8].
6. How to Code for Hypertension [6].