Provided herein is the use of measurements of cell-free DNA, protein, and/or metabolite found in biofluid (e.g., urine) for identifying and treating organ injury. Provided herein are methods and compositions for monitoring, detecting, quantifying, and treating kidney injury in subjects suffering from or suspected of having an altered renal status by measuring amounts of cfDNA and one or more other markers, such as inflammation markers, apoptosis markers, protein, and DNA methylation.