Chronic renal failure
"CKD is a silent epidemic: many people don't notice symptoms until advanced stages. That's why we insist on detecting it early; as it progresses, the renal, cardiovascular and overall prognosis worsens, but we can stop it if we act early."
DR. NURIA GARCÍA FERNÁNDEZ
DIRECTOR. NEPHROLOGY DEPARTMENT
What is chronic kidney disease?
Chronic kidney disease (CKD) is the progressive and irreversible loss of kidney function, in which the kidneys can no longer adequately filter waste and excess fluid. It is considered chronic when it lasts more than 3 months and is accompanied by an estimated glomerular filtration rate below 60 mL/min/1.73 m2. In Spain, it affects approximately 15% of adults, and its two main causes are diabetes and high blood pressure.
Identifying chronic kidney disease early makes it possible to take action to slow its progression. Simple tests can determine risk: a blood test to calculate the estimated glomerular filtration rate (eGFR) and a urine sample to detect albuminuria.
Active collaboration with your nephrologist and a multidisciplinary team, together with a home-care plan, is essential to maintain the best possible quality of life.
What are the symptoms of chronic kidney failure?
Early symptoms
Chronic kidney disease (CKD) can progress for years without clear signs. Because the kidneys can compensate, many people don’t notice symptoms until advanced stages.
- Nocturia (getting up several times at night to urinate).
- Fatigue and general discomfort.
- Loss of appetite and unintentional weight loss.
- Changes in urine (amount, color, foamy appearance).
Advanced-stage symptoms
- Swelling (edema) in the ankles, hands, or eyelids.
- Nausea/vomiting, metallic taste, or bad breath.
- Itching and dry skin.
- Cramps, tingling, or restless legs.
- Difficulty concentrating, drowsiness, or confusion.
- Shortness of breath, especially when lying down.
Clinical Complications
CKD can affect several organs and systems. Close monitoring helps prevent and treat these complications:
- Cardiovascular: high blood pressure, heart failure, atherosclerosis, and an increased risk of heart attack or stroke.
- Mineral and bone: secondary hyperparathyroidism, renal osteodystrophy, and vascular/tissue calcifications; increased fracture risk.
- Hematologic: normocytic anemia due to erythropoietin deficiency; causes fatigue, pallor, and reduced exercise tolerance.
- Metabolic and endocrine: insulin resistance, dyslipidemia, possible hypothyroidism, and reproductive changes (irregular cycles, reduced fertility).
- Electrolyte and acid–base: hyperkalemia (arrhythmias), metabolic acidosis, and fluid retention (edema, shortness of breath).
- Neurologic: peripheral neuropathy (tingling, pain, weakness) and uremic encephalopathy (drowsiness, confusion, seizures in severe cases).
Do you have any of these symptoms?
If you suspect that you have any of the above symptoms,
you should consult a medical specialist for a diagnosis.
Why does chronic kidney disease occur?
CKD represents an imbalance between the kidney’s functional capacity and the workload it must handle.
The loss of functional nephrons triggers hyperfiltration in the remaining nephrons (overworking), which raises intraglomerular pressure and accelerates glomerulosclerosis (kidney scarring).
In addition, local and systemic inflammatory processes occur, along with accelerated biological aging associated with decreased levels of regulatory proteins such as Klotho.
What are the risk factors?
The main risk factors that contribute to the development and progression of CKD are:
- Advanced age
- High blood pressure (hypertension)
- Diabetes mellitus
- Cardiovascular disease
- Obesity
- Smoking
- Dyslipidemia (abnormal blood lipids)
- Excessive salt intake
- Use of nephrotoxic medications
How is chronic kidney failure diagnosed?
Confirming CKD requires more than a single lab test: the finding must persist for at least 3 months, and tests should be repeated to rule out temporary issues (dehydration, infections, strenuous exercise).
What tests will we do?
- A blood test to calculate the estimated glomerular filtration rate (eGFR), which indicates how much your kidneys “filter.” In some situations, another protein (cystatin C) is added to refine the result.
- A urine test (ideally the first morning sample) to measure the albumin-to-creatinine ratio (ACR). Persistent albumin suggests kidney damage.
- Blood pressure measurement and a medication review (some drugs can affect the kidneys).
- A kidney ultrasound to assess kidney size and shape and rule out obstructions.
- In selected cases, a kidney biopsy may be performed to determine the exact cause and choose the best treatment.
With this information, the team classifies CKD by level of kidney function and the amount of protein in the urine. This staging helps estimate risk, plan treatment, and set the frequency of follow-up visits.
How is chronic kidney failure treated?
The treatment of CKD is based on three fundamental pillars
Kidney-protective lifestyle habits
- Quit smoking. It’s one of the most effective measures.
- Moderate exercise: aim for 150 min/week (brisk walking, easy cycling, etc.), and avoid a sedentary lifestyle.
- Maintain a healthy weight and good sleep.
- Kidney-friendly eating:
- Low salt: about <5 g of salt/day (avoid processed foods and salty snacks).
- Adjusted protein: in advanced CKD, around 0.8 g/kg/day is often recommended (according to your case).
- More vegetables and whole, minimally processed foods; fewer ultra-processed products.
- Fluids: individualized amount (ask your care team; “more” isn’t always better).
- Avoid nephrotoxic medications without medical indication (e.g., NSAIDs like ibuprofen/naproxen) and check before taking herbs or supplements.
- Keep vaccinations up to date (flu, pneumococcal, etc.) as medically indicated.
Kidney-protective medications (as appropriate for you)
- ACE inhibitors/ARBs (renin–angiotensin system blockade): lower blood pressure and protect the kidneys, especially when albumin is present in the urine.
- SGLT2 inhibitors (for many patients with diabetes and some without diabetes): help slow progression and protect the heart.
- Statins: reduce cholesterol and cardiovascular risk, which is very important in CKD.
Depending on your situation, your team will adjust other treatments (diuretics, blood sugar and blood pressure control, correction of acidosis, etc.).
Monitoring and follow-up
- Blood pressure, blood sugar, lab tests (kidney function and urine albumin), and weight/edema monitoring at home.
- Regular check-ups to adjust medications and monitor potassium, anemia, and bone health.
The aim of secondary prevention is to slow the progression of chronic kidney disease and reduce cardiovascular risk. It requires periodic monitoring and a personalized plan with your care team.
Lowering protein in the urine (albuminuria)
- Low-salt diet to enhance the effect of medications.
- ACE inhibitors/ARBs: first-line medications to protect the kidneys.
- SGLT2 inhibitors: help slow CKD (with or without diabetes, as indicated).
- Nonsteroidal MRA (e.g., finerenone) in some patients with diabetes and persistent albuminuria.
Tight blood pressure control
- Individualized targets (often near 130/80 mmHg if tolerated).
- Combination therapy is common: ACE inhibitor/ARB + diuretic ± others.
Correcting common complications
- Anemia: monitor hemoglobin; treat with iron and, if needed, erythropoietin under medical supervision.
- Mineral and bone disorder: limit dietary phosphorus, use phosphate binders with meals, vitamin D if indicated.
- High potassium: adjust diet/medications; use potassium-lowering agents if necessary.
- Acidosis: your clinician may prescribe bicarbonate when appropriate.
If you have diabetes
- Good glucose control (individualized HbA1c target).
- In addition to SGLT2 inhibitors, GLP-1 receptor agonists may be indicated.
- Adjust doses of diabetes medications according to kidney function.
Indicated in advanced stages of CKD, usually with eGFR < 11–15 mL/min/1.73 m2 and persistent uremic symptoms (severe fatigue, nausea, loss of appetite, intense itching, fluid overload, neurological changes) despite medical treatment. The decision is planned in advance through shared decision-making and preparation of access (fistula, peritoneal catheter) or the transplant.
Dialysis
In-center hemodialysis (HD):
- At a hospital/specialized center, 3 sessions per week (≈4 h).
- Blood circulates through a dialyzer that “cleans” it and returns it to the body.
- Requires vascular access (fistula or graft).
Home dialysis
- Peritoneal dialysis (PD): uses the peritoneum as a natural membrane; fluid exchanges are performed via a catheter in the abdomen. It can be continuous ambulatory (CAPD) or automated overnight (APD; DP-A). Allows greater autonomy.
- Home hemodialysis: similar to in-center HD, but performed at home after training and with team support.
Kidney transplant
- Treatment of choice when feasible: better survival and quality of life.
- May be from a living or deceased donor.
- Requires lifelong immunosuppression and close follow-up.
Conservative management
For people who are not candidates for or do not wish to undergo renal replacement therapy (RRT), conservative management focuses on symptom control, nutritional, psychological, and social support, and palliative care aimed at the best possible quality of life.
What clinical trials do we have on insuficiencia renal crónica?
Where do we treat it?
IN NAVARRE AND MADRID
The Nephrology Service
of the Clínica Universidad de Navarra
The Nephrology Service of the Clínica Universidad de Navarra has more than five decades of experience, both in the diagnosis and treatment of all kidney pathologies and in the transplant of this organ.
Our specialists have completed their training in centers of national and international reference.
We have the best facilities in the Dialysis Unit in order to offer the highest quality care to our patients.
Diseases we treat
- Edemas and internal environment
- Kidney function studies
- Glomerulonephritis
- Arterial hypertension
- Acute kidney failure
- Chronic renal failure
- Use of diuretics
Why at the Clinica?
- National reference in kidney transplantation, pioneer in living donor kidney transplantation.
- Specialized nursing for the care and follow-up of our patients.
- Cardiovascular and renal damage prevention program.
Our team of professionals
Cardiovascular Checkup
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INTEGRATED CARDIOVASCULAR
ASSESSMENT PROGRAM
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The only checkup that incorporates the latest diagnostic imaging technology to accurately quantify your risk of stroke and myocardial infarction.
Thanks to the exclusive dedication of our professionals, we are able to perform the ICAP checkup in less than 48 hours with a highly accurate diagnosis.