Doctors can often see a large hiatus hernia on a chest x-ray. Otherwise, people are given barium in a liquid before x-rays are taken (barium swallow). The barium outlines the esophagus, making abnormalities easier to see. Hernias can also be seen during an upper endoscopy.
The kidneys filter the blood to remove wastes and produce urine. The ureters, urinary bladder, and urethra together form the urinary tract, which acts as a plumbing system to drain urine from the kidneys, store it, and then release it during urination.
As blood flows through the kidneys, creatinine is excreted out into your urine along with other waste products. Levels of creatinine in the urine taken over 24 hours, together with blood levels of creatinine, can be used to estimate the rate at which your kidneys do their filtering job.