Chronic Kidney Disease: Stages, Symptoms and the Medicines That Slow It Down
The kidneys filter the blood, remove waste and extra fluid, balance salts and acid, help control blood pressure, keep bones strong and signal the body to make red blood cells. When they are slowly damaged over months and years, that is chronic kidney disease, often shortened to CKD.
It is very common, affecting around one adult in ten, and most people who have it do not know. The kidneys have a large reserve, so symptoms rarely appear until much of their function is gone. The good news is that CKD found early can often be slowed dramatically, and newer medicines have made a real difference in the last few years.
This guide explains how kidney function is measured, the stages, the main causes, the treatments that protect the kidneys, the medicines to be careful with, and what happens if the kidneys eventually fail.
🧪 Two tests that tell the story
CKD is diagnosed with two simple tests, and both matter.
- eGFR (estimated glomerular filtration rate)
- A blood test that estimates how much blood the kidneys filter each minute. Normal is above 90. It falls gradually with age, and it can dip temporarily with dehydration or illness, so one low result is always repeated.
- Urine albumin to creatinine ratio (ACR)
- A urine test for protein leaking through the filters. Protein in urine is an early sign of damage and a strong predictor of how fast CKD will progress and of heart disease risk. It can be abnormal even when eGFR is normal.
CKD is diagnosed when either test stays abnormal for at least three months.
📊 The stages
| Stage | eGFR | What it usually means |
|---|---|---|
| 1 | 90 or above, with protein in urine or other damage | Normal filtering but signs of kidney damage |
| 2 | 60 to 89, with signs of damage | Mildly reduced; usually no symptoms |
| 3a | 45 to 59 | Mild to moderate; blood pressure and medicine doses need attention |
| 3b | 30 to 44 | Moderate to severe; anaemia and bone changes may begin |
| 4 | 15 to 29 | Severe; planning for possible dialysis or transplant starts |
| 5 | Below 15 | Kidney failure; dialysis, transplant or supportive care |
Many people, especially older adults, stay in stage 3 for the rest of their lives without ever needing dialysis. What matters most is the rate of decline and the amount of protein in the urine.
🔍 Symptoms, and why they come late
In the early stages there are usually no symptoms at all. As function falls further, people may notice:
- 😴 Tiredness and weakness, partly from anaemia
- 🦵 Swollen ankles, feet or around the eyes
- 🚽 Passing urine at night, or foamy urine from protein
- 🤢 Poor appetite, nausea and a metallic taste
- 🧴 Itchy skin and muscle cramps
- 💨 Breathlessness from fluid build-up
- 🧠 Poor concentration and restless legs
Because symptoms come so late, testing people at risk is essential: anyone with diabetes, high blood pressure, heart disease, a family history of kidney disease, or those over about 60.
🧩 What causes it
| Cause | Notes |
|---|---|
| Diabetes | The leading cause worldwide |
| High blood pressure | Both a cause and a consequence of CKD |
| Glomerulonephritis | Inflammation of the kidney filters, sometimes autoimmune |
| Polycystic kidney disease | An inherited condition with fluid-filled cysts |
| Blockage or reflux | Enlarged prostate, stones, or repeated kidney infections, covered in our guide to kidney infections |
| Long-term medicines | Regular anti-inflammatory painkillers, lithium and some others |
💊 Medicines that protect the kidneys
Treatment has two goals: slow the kidney damage, and protect the heart, because heart disease is the main risk for people with CKD. Several medicines do both.
| Medicine group | How it helps | Things to know |
|---|---|---|
| SGLT2 inhibitors (dapagliflozin and others) | Slow the decline in kidney function and reduce heart failure and death, with or without diabetes | Now a foundation of CKD treatment for many people; a small early dip in eGFR is expected and is not harmful |
| ACE inhibitors or ARBs (lisinopril, losartan) | Lower blood pressure and reduce protein leakage | Blood tests for potassium and creatinine after starting and after dose changes |
| Statins | Reduce heart attacks and strokes, which are common in CKD | Recommended for most adults with CKD over 50 |
| Diuretics | Remove extra fluid and help control blood pressure | Doses are adjusted as kidney function changes |
In our catalogue these include Dapavel (Dapagliflozin), Cozaar (Losartan), Zestril (Lisinopril), Lipitor (Atorvastatin) and Lasix (Furosemide). All of them should be started and adjusted by a doctor with regular blood tests.
💡 Sick day rules. If you are vomiting, have diarrhoea or a fever and cannot keep fluids down, temporarily stop medicines such as SGLT2 inhibitors, ACE inhibitors, ARBs, diuretics and metformin, and restart them once you are eating and drinking normally for a day or two. Ask your doctor for a written plan. Dehydration with these medicines can cause a sudden drop in kidney function.
⚠️ Medicines to be careful with
🔴 With CKD, check with a doctor or pharmacist before taking:
- Anti-inflammatory painkillers such as ibuprofen, naproxen and diclofenac tablets — they reduce blood flow to the kidneys. Paracetamol is usually safer
- Potassium supplements and salt substitutes containing potassium — potassium can build up to dangerous levels. Our guide to high potassium explains the risks
- Some antibiotics and antivirals, which need lower doses
- Metformin — the dose is reduced at lower eGFR and it is stopped when function is very low
- Herbal remedies, some of which damage the kidneys
- Contrast dye for scans, where extra precautions may be needed
🥗 Everyday measures
- Blood pressure
- Usually aimed below about 130/80, especially with protein in the urine.
- Blood sugar
- Good control in diabetes slows kidney damage.
- Salt
- Less salt helps blood pressure and swelling. Avoid potassium-based salt substitutes unless your doctor agrees.
- Protein
- Moderate amounts are advised; very high-protein diets and supplements can strain the kidneys.
- Potassium and phosphate
- Restriction is only needed if blood tests show high levels, and is best planned with a dietitian.
- Stop smoking and stay active
- Both protect the kidneys and heart.
🩸 Complications in later stages
As CKD advances, it affects other parts of the body. Anaemia develops because the kidneys make less of the hormone that stimulates red blood cells; it is treated with iron and sometimes injections. Bone and mineral problems arise from changes in phosphate, calcium and vitamin D. Acid build-up and high potassium may need treatment. Regular blood tests pick these up early.
🏥 When the kidneys fail
In stage 5, the options are discussed well in advance so there is time to prepare.
| Option | What it involves |
|---|---|
| Kidney transplant | The best long-term option for suitable people; can come from a living or deceased donor |
| Haemodialysis | Blood is cleaned by a machine, usually three times a week in a unit, or at home |
| Peritoneal dialysis | Fluid in the abdomen cleans the blood; done daily at home |
| Conservative care | For some older or frail people, treatment focused on symptoms and quality of life without dialysis |
📞 When to see a doctor
- Diabetes or high blood pressure — ask for yearly eGFR and urine protein tests
- Swelling of the legs or around the eyes, or foamy urine
- Passing much less urine than usual — promptly
- Breathlessness, confusion or severe weakness — urgently
- Vomiting or diarrhoea while on kidney or blood pressure medicines — follow sick day rules and seek advice
- Before starting any new medicine, including over-the-counter painkillers
❓ Frequently asked questions
What does eGFR mean?
eGFR, or estimated glomerular filtration rate, is a blood test estimate of how much blood the kidneys filter each minute. Above 90 is normal. Below 60 for three months or more indicates chronic kidney disease.
What are the early signs of kidney disease?
Usually there are none. Symptoms such as swelling, tiredness, foamy urine and night-time urination appear later. That is why people with diabetes, high blood pressure or heart disease should have regular blood and urine tests.
Can kidney disease be reversed?
Lost kidney function usually cannot be restored, but progression can often be slowed dramatically with blood pressure control, diabetes control and medicines such as SGLT2 inhibitors and ACE inhibitors or ARBs.
Does dapagliflozin help kidneys if I do not have diabetes?
Yes. Trials showed dapagliflozin slows kidney decline and reduces heart failure and death in people with chronic kidney disease both with and without diabetes. A small early dip in eGFR after starting is expected.
Which painkillers are safe with kidney disease?
Paracetamol is usually the safer choice. Anti-inflammatory painkillers such as ibuprofen, naproxen and diclofenac tablets can harm the kidneys and should be avoided unless a doctor advises otherwise.
What do the stages of CKD mean?
Stages 1 to 5 are based on eGFR, from normal filtering with signs of damage in stage 1 to kidney failure below 15 in stage 5. Many people stay in stage 3 for life. The speed of decline and protein in urine matter as much as the stage.
Why is protein in urine important?
It is an early sign of kidney damage and predicts faster decline and higher heart disease risk. Medicines such as ACE inhibitors, ARBs and SGLT2 inhibitors reduce it.
What diet is best for kidney disease?
Less salt, moderate protein, and restriction of potassium or phosphate only if blood tests show high levels. Avoid potassium-based salt substitutes unless your doctor agrees. A dietitian can tailor advice.
What are sick day rules?
When vomiting, having diarrhoea or unable to drink, temporarily stop medicines such as SGLT2 inhibitors, ACE inhibitors, ARBs, diuretics and metformin, and restart once eating and drinking normally. This prevents a sudden drop in kidney function.
When is dialysis needed?
Usually when eGFR falls below about 10 to 15 and symptoms or complications develop, such as fluid overload, high potassium or severe tiredness. Transplant, dialysis and conservative care are discussed well in advance.
📑 Sources and editorial
- International clinical practice guideline for the evaluation and management of chronic kidney disease
- Trials of SGLT2 inhibitors in chronic kidney disease with and without diabetes
- Guidance on ACE inhibitors and ARBs in proteinuric kidney disease
- Guidance on medicine safety and sick day rules in chronic kidney disease
- Guidance on dialysis, transplantation and conservative kidney management
- Related reading: kidney infections, high potassium
- Related products: Dapavel (Dapagliflozin), Cozaar (Losartan), Zestril (Lisinopril)
- RXshop Editorial Team — reviewed by Emily Chen, MD, Internal Medicine
Medical Disclaimer: The information in this article is for educational and informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek guidance from a qualified healthcare provider with any questions you may have regarding a medical condition, and before starting, stopping or changing any medication.