Diuretic Testing in Chronic Kidney Disease

This study is testing the response to water pills (diuretics) in people with moderate chronic kidney disease (CKD) compared to people with healthy kidneys. The goal is to better understand how the kidneys handle diuretics when they are not functioning at full capacity, which could guide better treatment decisions. **You may be eligible if...** - You have CKD stage G3 (kidney function at 30–59% of normal), confirmed at your last check-up - OR you are a healthy volunteer with kidney function normal for your age **You may NOT be eligible if...** - You have a known allergy or intolerance to diuretics - You are currently receiving chemotherapy for cancer - You have had a kidney transplant - You take calcineurin inhibitors or immunosuppressants for kidney disease - Your potassium levels are too high or too low - Your life expectancy is less than 12 months Talk to your doctor to see if this trial is right for you.