A GFR of less than 60ml/minute for three or more months indicates chronic kidney disease. A GFR of less than 15ml/minute indicates full failure of the kidneys. GFR estimates between 60 and 89 mL/minute do not mean a person has chronic kidney disease unless there are other signs of disease. People with either higher than normal amounts of muscle mass, such as bodybuilders or people with lower than normal amounts of muscle mass, such as amputees or people with muscle wasting disorders (when the muscles become less dense than normal) can have GFR test results that do not appear normal, but may still be normal. A medical professional will explain the meaning of any GFR test done on a patient.