Kidney Damage: Early Signs, Stages and Can Kidneys Recover?

Updated September 26, 2026

Author: Dr. Shabbir Hussain, BPT, Registered Physiotherapist
Medical topic: Kidney health and chronic kidney disease
Editorial note: Medical information in this article is based on guidance from NIDDK, the National Kidney Foundation and KDIGO. It is intended for general health education and does not replace evaluation by a physician or nephrologist.

Quick Answer

Kidney damage can begin quietly, without pain or obvious changes in urination. In many people, early chronic kidney disease is discovered only through blood and urine tests. Two important markers are eGFR and urine albumin, which can reveal kidney problems before more noticeable symptoms appear.

Whether damaged kidneys can recover depends on the cause. Acute kidney injury (AKI) may improve substantially when the underlying cause is treated, while established chronic kidney disease (CKD) generally cannot simply be reversed, although its progression can often be slowed.

What are the first signs of kidney damage?

One of the biggest misconceptions is that kidney damage always causes obvious symptoms.

In reality, early CKD often causes few or no symptoms. Kidney disease may first be discovered through routine blood and urine testing.

Two important tests are:

• eGFR: estimates how well the kidneys filter blood.
• uACR: measures the amount of albumin relative to creatinine in a urine sample and helps detect kidney damage.

Important: Kidney damage can exist even when eGFR is still relatively preserved. Persistent albumin in urine—measured using the urine albumin-to-creatinine ratio (uACR)—can be an early marker of kidney disease.

As kidney function becomes more impaired, symptoms can include fatigue, swelling, changes in urination, itching, muscle cramps, nausea, vomiting and reduced appetite.

Foamy urine can occur when protein is leaking into the urine, although foamy urine alone does not mean that someone has kidney disease.

Can kidneys recover from damage?

Sometimes, but it depends on the type of kidney injury.

Acute kidney injury can develop rapidly because of problems such as severe dehydration, urinary blockage, severe illness or certain medications. Because the cause may be reversible, kidney function can improve after appropriate treatment.

Established CKD is different. Long-term structural damage generally cannot simply be repaired, but treatment can help preserve remaining kidney function and reduce the risk of progression.

What is the first stage of kidney damage?

G1 CKD means an eGFR of 90 or higher, but this number alone does not mean you have kidney disease. G1 is classified as CKD when there is other evidence of kidney damage, such as persistent albuminuria or another recognized kidney abnormality.

G2 CKD means an eGFR of 60–89 with evidence of kidney damage. For CKD, the evidence of kidney damage or reduced kidney function generally needs to persist for at least three months.

What happens if you have kidney damage?

The outcome depends on its cause, severity and whether it is acute or chronic.

Progressive CKD can eventually lead to complications such as high blood pressure, anemia, electrolyte abnormalities, bone and mineral problems and cardiovascular disease.

When kidney function reaches kidney failure, treatment may include dialysis, kidney transplantation, or other forms of supportive care, depending on the person’s health and treatment goals.

The important point is that kidney damage does not automatically mean kidney failure. Because early CKD often causes no symptoms, blood and urine testing can help detect kidney disease before it becomes advanced.

When should you get your kidneys checked?

Consider discussing kidney testing with a healthcare professional if you have:

• diabetes
• high blood pressure
• heart disease
• a family history of kidney disease
• persistent swelling
• significant changes in urination
• blood in the urine
• unexplained persistent fatigue

NIDDK identifies diabetes, hypertension, heart disease and family history as important CKD risk factors, and notes that testing may be the only way to detect kidney disease in its earlier stages.

How Physiotherapy Can Help

Physiotherapy does not repair damaged kidneys, but physical rehabilitation can be useful for people living with chronic kidney disease or receiving dialysis.

Depending on the person’s medical status, a physiotherapist may help with:

• Safe strength and mobility exercises
• Maintaining physical function and independence
• Managing deconditioning and fatigue
• Exercise planning around dialysis treatment when appropriate

Exercise intensity should be individualized, particularly in people with advanced CKD, cardiovascular disease, anemia or other complications.

Exercise intensity should be individualized, particularly in people with advanced CKD, cardiovascular disease, anemia or other complications. People receiving dialysis or with significant medical complications should coordinate exercise planning with their healthcare and dialysis team.

Key Takeaway

Kidney damage can remain silent for a long time. If you have diabetes, high blood pressure, cardiovascular disease or a family history of kidney disease, discussing eGFR and urine albumin testing with your healthcare professional can help detect kidney problems earlier.

Medical Sources

• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) — What Is Chronic Kidney Disease in Adults? NIDDK — Chronic Kidney Disease
• National Kidney Foundation — Estimated GFR (eGFR) Test: Kidney Function Levels, Stages, and What to Do Next National Kidney Foundation — eGFR
• NIDDK — Albuminuria: Albumin in the Urine NIDDK — Albuminuria
• National Kidney Foundation — How to Classify CKD National Kidney Foundation — CKD Classification

Medical Disclaimer

This article is for general educational and informational purposes only. It is not a substitute for professional medical diagnosis, treatment, or individualized medical advice. If you have persistent, severe, worsening, or concerning symptoms, consult a qualified healthcare professional. Seek urgent medical care for emergency symptoms.