Chronic kidney disease

Chronic kidney disease (CKD) is the gradual loss of kidney function over months or years. The kidneys filter wastes and excess fluid from the blood; when function declines, dangerous levels of fluid, electrolytes, and wastes can build up. CKD also increases the risk of heart disease and stroke.

Early CKD often has no symptoms and is detected through blood and urine tests. Diabetes and high blood pressure are the leading causes. Progression can often be slowed with blood-pressure and blood-sugar control, medicines that protect the kidneys, lifestyle measures, and treatment of complications. Advanced CKD may require dialysis or kidney transplantation.

Symptoms are uncommon in early stages. As kidney function worsens, people may experience:

• Nausea and vomiting
• Loss of appetite
• Fatigue and weakness
• Sleep problems
• Changes in urination (more or less, foamy urine)
• Decreased mental sharpness
• Muscle twitches and cramps
• Swelling of feet and ankles
• Persistent itching
• Chest pain (if fluid builds up around the heart)
• Shortness of breath (from fluid in the lungs or anemia)
• High blood pressure that is hard to control

Because symptoms appear late, routine screening in people with diabetes, hypertension, or other risk factors is essential.

CKD results from conditions that damage the kidneys over time. The most common causes are:

• Diabetes mellitus (type 1 and type 2)
• High blood pressure (hypertension)
• Glomerulonephritis (inflammation of the kidney’s filtering units)
• Interstitial nephritis
• Polycystic kidney disease and other inherited disorders
• Prolonged obstruction of the urinary tract (stones, enlarged prostate, cancers)
• Vesicoureteral reflux
• Recurrent kidney infection
• Autoimmune diseases (lupus, etc.)
• Certain medicines and toxins with long-term exposure

Risk factors include:

• Diabetes
• High blood pressure
• Heart disease
• Smoking
• Obesity
• Family history of kidney disease
• Abnormal kidney structure
• Older age
• Frequent use of medicines that can affect the kidneys (e.g., long-term NSAIDs)
• History of acute kidney injury
• Belonging to populations with higher rates of CKD (including African American, Hispanic, American Indian, and Asian American groups, partly related to higher rates of diabetes and hypertension)

CKD can lead to:

• Fluid retention and swelling, pulmonary edema
• Hyperkalemia (high potassium) that can affect heart rhythm
• Heart disease and stroke
• Weak bones and increased fracture risk (mineral and bone disorder)
• Anemia
• Decreased libido and erectile dysfunction
• Pericarditis
• Pregnancy complications
• Irreversible kidney failure (end-stage kidney disease) requiring dialysis or transplant
• Depression and reduced quality of life

The most effective ways to prevent or delay CKD are:

• Control blood sugar if you have diabetes
• Keep blood pressure in target range
• Do not smoke
• Maintain a healthy weight
• Use NSAIDs only as advised and avoid unnecessary exposure to kidney-toxic medicines
• Treat urinary tract infections and obstruction promptly
• Follow a heart-healthy diet with attention to sodium
• Stay physically active

People at high risk should have periodic testing of eGFR and urine albumin.

CKD is diagnosed and staged using:

• eGFR (estimated glomerular filtration rate) from blood creatinine — defines stage when reduced for ≥3 months
• Urine albumin-to-creatinine ratio (UACR) — detects kidney damage
• Urinalysis and other blood tests (electrolytes, hemoglobin, calcium, phosphorus, PTH)
• Imaging (ultrasound) to assess size and structure
• Kidney biopsy in selected cases to determine the underlying disease

Staging (G1–G5) combined with albuminuria categories (A1–A3) guides prognosis and treatment intensity.

See a healthcare professional if you have risk factors for CKD (diabetes, high blood pressure, family history of kidney disease) or symptoms such as unexplained fatigue, swelling, or changes in urination. Seek urgent care for sudden decrease in urine output, severe swelling, chest pain, or severe shortness of breath.

People with known CKD should keep regular nephrology and primary-care follow-up and report new or worsening symptoms promptly.

Treatment aims to slow progression, reduce cardiovascular risk, and manage complications:

• Blood-pressure control — often with ACE inhibitors or ARBs, which also reduce proteinuria
• SGLT2 inhibitors — kidney and heart protection in many patients with CKD, with or without diabetes
• Finerenone and other agents in selected patients with diabetic kidney disease
• Glycemic control in diabetes (with preference for kidney-protective agents)
• Statin therapy for cardiovascular risk reduction
• Dietary counseling — sodium restriction; protein, potassium, and phosphorus adjustments as needed
• Anemia management — iron, erythropoiesis-stimulating agents when indicated
• Mineral and bone disorder — phosphate binders, vitamin D analogues, calcimimetics as appropriate
• Avoidance of nephrotoxins
• Dialysis or transplantation for kidney failure

Early nephrology referral improves outcomes for progressive or advanced CKD.

Daily self-management includes:

• Taking prescribed medicines consistently
• Monitoring blood pressure at home if advised
• Following the recommended eating pattern and fluid guidance
• Not smoking
• Staying active within recommended limits
• Avoiding over-the-counter NSAIDs unless cleared by a clinician
• Attending all laboratory and clinic appointments
• Reporting swelling, reduced urine, severe fatigue, or chest symptoms promptly

Bring:

• List of medical conditions and all medicines/supplements
• Home blood-pressure readings if available
• Previous kidney test results (eGFR, creatinine, urine albumin)
• Family history of kidney disease
• Questions about stage, rate of progression, medicines that protect the kidneys, diet, and when dialysis or transplant might be discussed