A Clear Guide to the 5 Stages of Kidney Disease

Your kidneys are vital organs that often work silently, so it’s smart to understand how they function and what to look for when things go wrong. Many people are unaware of kidney problems until they become serious. This guide provides a clear, detailed breakdown of the stages of kidney disease, the subtle symptoms, and the important warning signs you should know.

What Do Your Kidneys Do?

Before diving into the stages of disease, it’s helpful to know what healthy kidneys do. Think of them as your body’s advanced filtration system. These two bean-shaped organs, located just below your rib cage, work around the clock to:

  • Remove waste products and excess fluid from your blood.
  • Balance your body’s fluids and minerals, like salt, potassium, and calcium.
  • Produce hormones that control blood pressure, make red blood cells, and keep your bones strong.

Chronic kidney disease (CKD) occurs when your kidneys are damaged and can’t filter blood as well as they should. This damage happens slowly over a long period, which is why symptoms often don’t appear until the later stages.

How Kidney Function is Measured: Understanding eGFR

Doctors measure kidney function using a simple blood test that calculates your estimated Glomerular Filtration Rate, or eGFR. This number shows how well your kidneys are filtering waste from your blood. A higher eGFR number is better. The stages of kidney disease are based on this eGFR level.

  • Normal eGFR: A healthy person’s eGFR is typically 90 or above.
  • Declining eGFR: As kidney function declines, the eGFR number goes down.

Understanding your eGFR is the key to knowing which stage of kidney disease you might be in.

The 5 Stages of Chronic Kidney Disease Explained

CKD is divided into five distinct stages, from very mild damage to complete kidney failure. Knowing the stage helps doctors create the best treatment plan to slow the progression of the disease.

Stage 1: eGFR of 90 or Higher

In Stage 1, there is mild kidney damage, but the kidneys are still functioning at a normal or near-normal level. Most people have no symptoms at all. Often, the only sign of damage is the presence of protein in the urine (proteinuria), which might be discovered during a routine check-up.

  • What it means: The kidneys are still doing their job well, but there are early signs of a problem.
  • Common Symptoms: Usually none.
  • Goal of Treatment: The focus is on slowing the progression of the disease by managing underlying conditions like high blood pressure or diabetes.

Stage 2: eGFR Between 60 and 89

Stage 2 indicates a mild loss of kidney function. Like Stage 1, many people still do not experience any noticeable symptoms because the kidneys are compensating for the damage. The diagnosis is often made when a person is being tested for another condition.

  • What it means: The kidneys are not filtering as efficiently as they should, but they are still managing most of their tasks.
  • Common Symptoms: Generally none, though some may have high blood pressure or protein in their urine.
  • Goal of Treatment: Continue to manage blood pressure and blood sugar, adopt a kidney-friendly diet, and avoid medications that can harm the kidneys, such as nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen.

Stage 3: eGFR Between 30 and 59

This is the stage where symptoms often begin to appear, as waste products start to build up in the body. Stage 3 is divided into two sub-stages:

  • Stage 3a (eGFR 45-59): A moderate decrease in kidney function.

  • Stage 3b (eGFR 30-44): A moderate-to-severe decrease in kidney function.

  • What it means: The kidneys have sustained significant damage, and their ability to filter waste is noticeably impaired. Complications like anemia (low red blood cell count) and early bone disease can develop.

  • Common Symptoms:

    • Fatigue or feeling tired all the time.
    • Swelling in the hands, feet, or ankles (edema).
    • Changes in urination (more or less frequent).
    • Back pain (in the area of the kidneys).
    • Dry, itchy skin.

  • Goal of Treatment: A doctor or a specialist called a nephrologist will work to manage symptoms and complications. This often involves medication, dietary changes, and regular monitoring.

Stage 4: eGFR Between 15 and 29

Stage 4 signifies a severe loss of kidney function. This is the last stage before kidney failure. It is crucial to have regular appointments with a nephrologist to prepare for the possibility of dialysis or a kidney transplant.

  • What it means: The kidneys are close to failing. Waste buildup is significant, leading to more pronounced symptoms.
  • Common Symptoms: In addition to Stage 3 symptoms, a person may experience:
    • Nausea and vomiting.
    • A metallic taste in the mouth or bad breath.
    • Loss of appetite.
    • Difficulty concentrating.
    • Shortness of breath.
  • Goal of Treatment: Prepare for end-stage renal disease (ESRD). This includes education about treatment options like different types of dialysis and the kidney transplant process.

Stage 5: eGFR Below 15

This is the final stage, known as end-stage renal disease (ESRD) or kidney failure. At this point, the kidneys have lost nearly all of their ability to function. Without treatment, waste and fluid build up to dangerous levels in the body.

  • What it means: The kidneys have failed or are very close to failing.
  • Common Symptoms: The symptoms from Stage 4 become more severe, and life-threatening complications can occur.
  • Goal of Treatment: Life-sustaining treatment is necessary. The two main options are:
    • Dialysis: A procedure that artificially filters waste from the blood.
    • Kidney Transplant: A surgical procedure to place a healthy kidney from a donor into the body.

Red Flags and Silent Symptoms You Should Never Ignore

Because early-stage kidney disease is often silent, it’s vital to recognize the subtle warning signs. If you experience several of these, especially if you have risk factors like diabetes or high blood pressure, it’s important to speak with your doctor.

  • You’re More Tired Than Usual: A buildup of toxins can cause severe fatigue. Kidneys also produce a hormone that helps make red blood cells, and a decline can lead to anemia, which also causes weakness.
  • Puffiness Around Your Eyes: This is an early sign that your kidneys are leaking a large amount of protein into the urine rather than keeping it in the body.
  • Swollen Feet and Ankles: Decreased kidney function can lead to sodium retention, causing swelling in your lower extremities.
  • Changes in Urination: Pay attention to needing to urinate more often (especially at night), seeing blood in your urine, or having foamy or bubbly urine (a sign of protein).
  • Dry and Itchy Skin: When kidneys can’t maintain the right balance of minerals and nutrients in your blood, it can lead to severe itching.
  • Poor Appetite or a Metallic Taste: A buildup of waste in the blood (uremia) can make food taste different and reduce your appetite.

Frequently Asked Questions

Who is at the highest risk for kidney disease? The main risk factors are diabetes and high blood pressure, which are responsible for the majority of cases. Other risk factors include a family history of kidney failure, heart disease, obesity, and being over the age of 60.

Can kidney damage be reversed? While acute kidney injury can sometimes be reversed, chronic kidney disease damage is generally not reversible. However, with early diagnosis and proper management, its progression can often be slowed down significantly, preserving kidney function for many years.

What can I do to protect my kidneys? Managing blood pressure and blood sugar are the most important steps. Additionally, you can protect your kidneys by reducing salt intake, drinking enough water, avoiding the overuse of NSAID pain relievers, maintaining a healthy weight, and not smoking.