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.
Poor Sleep Habits. A woman yawns over coffee due to being sleepy from poor sleep habits. Tetra Images - Jamie Grill/Brand X Pictures/Getty Images. The most common cause of always feeling too sleepy or drowsy during the daytime might be the most obvious: you are simply not getting enough sleep at night.