Learn About Stage 4 Kidney Disease and Treatment Options

What Is Stage 4 Kidney Disease?

Stage 4 chronic kidney disease (CKD) is a serious condition where the kidneys have lost a significant amount of their ability to filter waste from the blood. In this stage, kidney function has declined to between 15 and 29 percent of normal capacity. The kidneys are bean-shaped organs about the size of your fist that filter waste products and excess water from your blood to form urine. When the kidneys don't work properly, waste builds up in your body, which can cause health problems.

The National Kidney Foundation estimates that approximately 37 million Americans have chronic kidney disease, though many don't know it. Stage 4 is considered advanced kidney disease but not yet kidney failure. At this stage, most people haven't started dialysis or received a kidney transplant yet, though these treatments may be needed in the near future. Understanding what Stage 4 means helps you work with your healthcare team to slow the disease's progression and manage your health.

The glomerular filtration rate (GFR) is the main measure doctors use to determine kidney function. Your GFR is a number that shows how many milliliters of waste your kidneys can filter from your blood each minute. A normal GFR is 90 or higher. At Stage 4, your GFR falls between 15 and 29, indicating severe reduction in kidney function. This measurement comes from a simple blood test that measures creatinine, a waste product your muscles produce.

Many people with Stage 4 kidney disease don't experience obvious symptoms at first. However, as kidney function declines further, symptoms may include fatigue, swelling in the ankles and feet, shortness of breath, trouble sleeping, decreased appetite, and changes in how often you urinate. Some people may develop high blood pressure or anemia (low red blood cells), which can make them feel tired and weak.

Practical Takeaway: Track your GFR and creatinine levels from your blood work. Keep a record of these numbers over time to see how your kidney function is changing. Ask your doctor what your specific numbers mean and how often you should have them checked, typically at least once or twice yearly at this stage.

What Causes Stage 4 Kidney Disease?

The most common causes of Stage 4 chronic kidney disease are diabetes and high blood pressure. Together, these two conditions account for about 65 percent of all chronic kidney disease cases in the United States. Diabetes damages the small blood vessels in the kidneys that filter waste. High blood pressure puts extra strain on these same blood vessels. Having either condition increases your risk; having both significantly increases the danger.

Diabetes causes kidney damage through a condition called diabetic nephropathy. High blood sugar levels harm the glomeruli—the tiny filtering units inside the kidneys. Over time, these damaged glomeruli scar and stop working properly. About 1 in 4 people with diabetes develop chronic kidney disease. The risk is higher in people with Type 1 diabetes who have had the disease for many years or whose blood sugar hasn't been well controlled.

High blood pressure harms the kidneys by damaging the blood vessels that filter waste. The pressure causes these vessels to thicken and narrow, reducing blood flow to the kidneys. This decreased blood flow means the kidneys cannot filter waste efficiently. About 1 in 5 adults with high blood pressure develops chronic kidney disease. People with both diabetes and high blood pressure face the highest risk of kidney disease progression.

Other causes of Stage 4 kidney disease include glomerulonephritis (inflammation of the kidney's filtering units), polycystic kidney disease (an inherited disorder where cysts grow in the kidneys), chronic pyelonephritis (long-term kidney infections), kidney stones, and autoimmune diseases like lupus. Some medications, including certain painkillers used long-term and some blood pressure drugs, can also damage kidneys. Chronic dehydration, obesity, smoking, and a family history of kidney disease increase your risk as well.

Age matters too. Kidney function naturally declines with age, even in people without kidney disease. People over 65 face a higher risk of developing Stage 4 kidney disease. African Americans, Native Americans, and Hispanic Americans develop kidney disease at higher rates than other groups, partly due to higher rates of diabetes and high blood pressure in these populations and partly for reasons scientists are still studying.

Practical Takeaway: Learn which conditions you have that affect kidney health. If you have diabetes, work to keep your blood sugar in your target range. If you have high blood pressure, take your medications as prescribed and monitor your blood pressure at home. These actions can slow kidney disease progression significantly.

How Is Stage 4 Kidney Disease Diagnosed?

Doctors diagnose Stage 4 kidney disease using blood and urine tests combined with your medical history. The main blood test measures creatinine, a waste product filtered by healthy kidneys. Your doctor uses your creatinine level, along with your age, sex, race, and body size, to calculate your GFR. This calculation estimates what percentage of normal kidney function you have. A GFR between 15 and 29 indicates Stage 4 disease.

A urine test checks for protein or blood in your urine, which indicates kidney damage. Healthy kidneys don't allow protein to pass into urine, so protein in the urine is a sign that the kidney's filtering units aren't working properly. Your doctor may measure how much protein you're spilling into your urine over 24 hours by having you collect all your urine for one full day. Alternatively, they may calculate the protein-to-creatinine ratio from a single urine sample, which provides similar information more conveniently.

Imaging studies may be ordered to get a clearer picture of your kidneys' structure. Ultrasound is often used because it's safe, doesn't expose you to radiation, and shows the kidneys' size and shape. Doctors look for scarring, cysts, or other abnormalities. In some cases, a CT scan or MRI might be recommended if doctors need more detail about your kidney structure or suspect a specific cause like kidney stones or tumors.

Your doctor will ask detailed questions about your medical history, including whether you have diabetes, high blood pressure, heart disease, or a family history of kidney disease. They'll ask about medications you take, including over-the-counter painkillers, as these can harm kidneys. They'll also ask about your symptoms, lifestyle habits like smoking, alcohol use, and diet. This information helps your doctor understand what may have caused your kidney disease and how to manage it.

Once Stage 4 is diagnosed, your doctor typically refers you to a nephrologist—a doctor who specializes in kidney disease. The nephrologist reviews your test results, performs a thorough examination, and discusses treatment options with you. They'll also help you prepare for future treatment if your kidney function continues to decline. Some nephrology clinics use a team approach with nephrologists, nurses, social workers, and dietitians all working together.

Practical Takeaway: Request copies of all your test results and keep them organized. Write down your GFR and urine protein levels over time. Bring these records to all doctor appointments so you and your healthcare team can track changes and adjust your treatment plan as needed.

Medical Management and Treatment Options for Stage 4 Kidney Disease

The main goal of treating Stage 4 kidney disease is to slow the rate at which kidney function declines and manage complications. This typically involves controlling blood pressure, managing blood sugar if you have diabetes, reducing protein in the urine, and managing other health conditions. These measures can significantly delay the progression to kidney failure requiring dialysis or transplant. Studies show that people who actively manage their kidney disease often slow its progression by 30 to 50 percent.

Blood pressure control is critical in Stage 4 kidney disease. Most people with kidney disease are prescribed medications called ACE inhibitors or angiotensin receptor blockers (ARBs). These drugs lower blood pressure and also protect the kidneys by reducing pressure within the kidney's filtering units. Common ACE inhibitors include lisinopril and enalapril. Common ARBs include losartan and valsartan. Your target blood pressure with kidney disease is usually less than 130/80 mmHg. Your doctor may prescribe additional blood pressure medications like beta-blockers, calcium channel blockers, or diuretics if needed to reach this goal.

If you have diabetes, controlling your