Renal (Kidney) Impairment: Renal (Kidney) Impairment can be defined as a condition in which the kidneys lose the ability to remove waste and balance fluids. Loss of kidney function can cause symptoms such as decreased urine output, shortness of breath, fatigue, confusion, nausea, or fluid retention causing swelling in your legs, ankles, or feet. Renal Impairment may require immediate medical attention depending on severity. Click below to participate in a study.