Ketostix urine reagent test strips are designed to measure the presence and concentration of acetoacetic acid in the urine. Acetoacetic acid is a naturally occurring keto acid, which is also known as diacetic acid. This acid is produced by the liver and kidneys and can be used as an energy source by the heart and brain. However, people suffering from diabetes may not have a strong metabolism, which can result in abundance of ketone bodies. It is importance to keep a check on the level of acetoacetic acid as it can cause medical issues and complications.