Renal Disease
What is Renal disease?
Renal disease, also called kidney disease, happens when your kidneys lose their ability to filter waste and excess fluid from your blood. Your kidneys are two bean-shaped organs that work hard every day to clean your blood and remove toxins through urine. When they become damaged, waste products and fluids can build up in your body and cause serious health problems.
Kidney damage can develop slowly over months or years, often without any obvious symptoms at first. This is why many people don't realize they have renal disease until it has progressed. The condition ranges from mild kidney dysfunction to complete kidney failure, which requires dialysis or a transplant to stay alive.
Early detection through blood testing gives you the best chance to slow or stop kidney damage. Many people can protect their remaining kidney function through lifestyle changes and medical care. Catching renal disease early means you have more options to preserve your health.
Symptoms
Many people with early renal disease have no symptoms at all. As kidney function declines, you may notice:
- Fatigue and weakness that doesn't improve with rest
- Swelling in your ankles, feet, hands, or face
- Changes in urination, including more frequent nighttime urination or foamy urine
- Decreased urine output or difficulty urinating
- Nausea, vomiting, or loss of appetite
- Trouble concentrating or mental fog
- Muscle cramps or twitching
- Persistent itching of the skin
- Shortness of breath from fluid buildup
- High blood pressure that's hard to control
Many people feel completely fine in the early stages of kidney disease. This makes regular blood testing essential, especially if you have risk factors like diabetes or high blood pressure.
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Causes and risk factors
Renal disease develops when something damages the tiny filtering units inside your kidneys called nephrons. Diabetes and high blood pressure are the two most common causes, responsible for about two-thirds of all cases. High blood sugar from diabetes damages blood vessels in the kidneys over time. High blood pressure puts extra strain on the delicate filtering system and weakens it.
Other causes include autoimmune diseases like lupus, chronic urinary tract infections, kidney stones that cause blockages, genetic conditions like polycystic kidney disease, and prolonged use of certain medications. Your risk increases if you're over age 60, have a family history of kidney disease, smoke cigarettes, are overweight, or have heart disease. People of African, Hispanic, Asian, or Native American descent face higher risk as well.
How it's diagnosed
Renal disease is diagnosed primarily through blood tests that measure how well your kidneys filter waste. The most important markers are creatinine, blood urea nitrogen, and the BUN to creatinine ratio. Creatinine is a waste product from muscle breakdown that healthy kidneys remove from your blood. When creatinine levels rise, it signals that your kidneys aren't filtering properly. Blood urea nitrogen measures another waste product that builds up when kidneys fail. The ratio between these two markers helps doctors understand the type and severity of kidney problems.
Rite Aid offers kidney function testing through our add-on panel at Quest Diagnostics locations nationwide. Your doctor may also order urine tests to check for protein or blood, imaging tests like ultrasound or CT scans, and sometimes a kidney biopsy. Regular monitoring through blood work helps catch kidney disease early when treatment is most effective.
Treatment options
Treatment for renal disease focuses on slowing damage and managing the underlying causes:
- Control blood sugar levels if you have diabetes through diet, exercise, and medication
- Lower blood pressure with medication and lifestyle changes to protect kidney function
- Reduce protein intake to ease the workload on your kidneys
- Limit sodium to 2,300 mg per day to control blood pressure and reduce swelling
- Stay hydrated but follow your doctor's guidance on fluid intake
- Exercise regularly with at least 150 minutes of moderate activity per week
- Quit smoking to improve blood flow to your kidneys
- Avoid medications that can damage kidneys, including NSAIDs like ibuprofen
- Take prescribed medications like ACE inhibitors or ARBs to protect kidney function
- Work with a kidney specialist called a nephrologist for advanced disease
Severe kidney failure may require dialysis to filter your blood artificially or a kidney transplant. Early intervention with lifestyle changes can prevent many people from reaching this stage.
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- Simple blood draw at your nearest lab
- Results in days, not weeks
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Frequently asked questions
Renal disease and kidney disease are the same condition with different names. Renal comes from the Latin word for kidney. Healthcare providers use both terms interchangeably to describe any condition where the kidneys lose their ability to filter blood properly.
Early stage kidney disease can sometimes be reversed or stopped from progressing with aggressive treatment. This includes controlling diabetes and blood pressure, losing weight, and making dietary changes. Once kidney damage becomes severe, it cannot be fully reversed, but progression can still be slowed significantly.
If you have diabetes, you should get kidney function blood tests at least once per year. Your doctor may recommend testing every three to six months if you have other risk factors or early signs of kidney problems. Regular monitoring catches changes early when treatment works best.
People with kidney disease should limit high-sodium foods like processed meats and canned soups, potassium-rich foods like bananas and potatoes if levels are high, and phosphorus from dairy products and cola drinks. Your doctor may also recommend reducing protein intake from meat, fish, and beans depending on your stage of kidney disease.
Most people with chronic kidney disease do not experience pain, which is why the condition often goes undetected. Pain may occur if you have kidney stones, a kidney infection, or polycystic kidney disease with enlarged cysts. Back pain near the kidneys is not a common symptom of typical kidney disease.
Normal creatinine levels typically range from 0.7 to 1.3 mg/dL for men and 0.6 to 1.1 mg/dL for women. However, normal ranges can vary based on age, muscle mass, and laboratory standards. Your doctor looks at trends over time rather than a single number to assess kidney function.
Staying properly hydrated helps healthy kidneys work efficiently and can prevent kidney stones. However, drinking extra water cannot reverse existing kidney damage or significantly improve kidney function once disease has developed. In advanced kidney disease, you may actually need to limit fluid intake to prevent overload.
Some types of kidney disease are hereditary, including polycystic kidney disease and certain genetic disorders like Alport syndrome. Having a family history of kidney disease also increases your risk for developing it. If kidney disease runs in your family, regular screening with blood tests is especially important.
Dialysis typically becomes necessary at stage 5 kidney disease, also called end-stage renal disease or kidney failure. This happens when your kidneys function at less than 15 percent of normal capacity and can no longer keep you healthy on their own. Your doctor considers symptoms, lab results, and quality of life when recommending dialysis.
Yes, certain medications can damage kidneys over time, especially when taken regularly in high doses. NSAIDs like ibuprofen and naproxen, some antibiotics, proton pump inhibitors, and certain chemotherapy drugs can harm kidney function. Always tell your doctor about all medications and supplements you take so they can monitor your kidney health.