By Mayo Clinic Staff. An X-ray is a quick, painless test that produces images of the structures inside your body â particularly your bones. X-ray beams pass through your body, and they are absorbed in different amounts depending on the density of the material they pass through.
Physical Causes. The most obvious reason for being tired and sleepy is lack of sleep. According to MayoClinic.com, the average adult needs between seven and eight hours of sleep every day. If you're sleeping less than that, adjusting your sleeping schedule might provide some relief.
If your tiredness is the result of sleep deprivation, taking a short nap in the middle of the afternoon can give your energy levels a boost. You're most likely to fall asleep is between noon and 4 p.m., which matches the low point of the body's circadian cycle.