Chronic Kidney Disease Doctor — Valencia

What is chronic kidney disease?

Chronic kidney disease (CKD) is the gradual, long-term loss of kidney function. Your kidneys filter waste and excess fluid from the blood, balance minerals such as potassium and phosphate, regulate blood pressure and help produce red blood cells and active vitamin D. When they are damaged over months or years, these tasks are progressively impaired.

CKD is defined as kidney damage — or a reduced glomerular filtration rate (GFR) below 60 mL/min/1.73m² — persisting for at least three months. Because the kidneys have a large functional reserve, many people feel completely well until a substantial amount of function has already been lost. This is precisely why screening and early diagnosis matter so much.

As a nephrologist at Hospital Vithas 9 de Octubre in Valencia, Dr. Juan Luis Villaro Gumpert assesses, stages and manages CKD for both Spanish and international patients, with particular attention to the continuity of care that expats often struggle to maintain.

The five stages of CKD

CKD is graded by estimated GFR (eGFR), calculated from a simple blood creatinine test:

• Stage 1 (eGFR ≥ 90): normal filtration but with evidence of kidney damage, such as protein in the urine.
• Stage 2 (eGFR 60–89): mildly reduced function with kidney damage.
• Stage 3a (eGFR 45–59) and 3b (eGFR 30–44): moderately reduced function; complications such as anaemia and bone-mineral disturbance can begin.
• Stage 4 (eGFR 15–29): severely reduced function; this is when preparation for dialysis or transplantation is discussed.
• Stage 5 (eGFR < 15): kidney failure, where dialysis or a transplant may be needed to sustain life.

The amount of protein (albumin) in the urine is staged alongside eGFR, because higher protein loss signals faster progression and greater cardiovascular risk.

What causes chronic kidney disease?

The two most common causes worldwide — and in Valencia — are diabetes and high blood pressure (hypertension). Sustained high glucose or pressure slowly damages the kidneys’ delicate filtering units.

Other important causes include glomerulonephritis (inflammation of the filtering units), polycystic kidney disease, recurrent kidney infections, prolonged obstruction from kidney stones or an enlarged prostate, and the long-term use of certain painkillers. Often more than one factor is at play.

Symptoms by stage

Early CKD (stages 1–3a) frequently causes no symptoms at all and is detected only through blood and urine tests. As disease advances, you may notice fatigue, swelling of the ankles or face, foamy or frothy urine, needing to pass urine at night (nocturia), and blood pressure that becomes harder to control. In advanced stages (4–5), poor appetite, nausea, itching, muscle cramps and breathlessness can appear. The silent nature of early CKD is the strongest argument for proactive testing.

Why early detection matters

Detecting CKD early changes everything. In the early stages, the right interventions can slow or halt progression, protecting you from ever needing dialysis. Early detection also allows timely treatment of complications — anaemia, bone disease and, crucially, the elevated cardiovascular risk that accompanies CKD. People with kidney disease are in fact more likely to suffer a heart attack or stroke than to reach kidney failure, so cardiovascular protection is a central part of care.

How CKD is managed

Treatment is tailored to your stage and underlying cause, and typically combines several elements:

• Blood pressure control, usually targeting below 130/80 mmHg, often with ACE inhibitors or ARBs that also reduce urinary protein.
• Treating the underlying cause — tight glucose control in diabetes, immunosuppression in some forms of glomerulonephritis.
• Newer kidney-protective medications, such as SGLT2 inhibitors, which slow progression in many patients.
• Dietary adjustments, including moderating salt, and individualised guidance on protein, potassium and phosphate.
• Managing complications, treating anaemia, bone-mineral disorder and acidosis as they arise.
• Planning ahead when needed, with timely, unhurried discussion of dialysis or transplantation in advanced disease.

Prognosis and continuity of care

Most people with CKD, especially when it is caught early, live full lives with stable kidney function. The outlook depends heavily on the underlying cause, how well blood pressure and protein loss are controlled, and how consistently care is followed up.

For expats in Valencia, fragmented care across countries and languages is a real risk to kidney health. Dr. Villaro provides clear, English-language explanations and structured records you can share with doctors elsewhere, so that monitoring continues seamlessly whether you are in Spain or abroad. If you have diabetes, hypertension or an abnormal kidney test result, an early consultation is the single most valuable step you can take.

References

1. Kidney Disease: Improving Global Outcomes (KDIGO). 2024 KDIGO Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. kdigo.org
2. Heerspink HJL, et al. Dapagliflozin in Patients with Chronic Kidney Disease. N Engl J Med. 2020;383:1436–1446. PubMed 32970396
3. Perkovic V, et al. Canagliflozin and Renal Outcomes in Type 2 Diabetes and Nephropathy (CREDENCE). N Engl J Med. 2019;380:2295–2306. PubMed 30990260
4. Levey AS, et al. A new equation to estimate glomerular filtration rate. Ann Intern Med. 2009;150(9):604–612. PubMed 19414839