Sometimes, dyspepsia is a more sudden, noticeable (acute) sensation. Depending on the cause of the dyspepsia, people may have other symptoms such as a poor appetite, nausea, constipation, diarrhea, flatulence, and belching. For some people, eating makes symptoms worse. For others, eating relieves symptoms.
An X-ray machine is essentially a camera. Instead of visible light, however, it uses X-rays to expose the film. X-rays are like light in that they are electromagnetic waves, but they are more energetic so they can penetrate many materials to varying degrees.
The soft tissue in your body is composed of smaller atoms, and so does not absorb X-ray photons particularly well. The calcium atoms that make up your bones are much larger, so they are better at absorbing X-ray photons. In the next section, we'll see how X-ray machines put this effect to work.-rays are basically the same thing as visible light rays. Both are wavelike forms of electromagnetic energy carried by particles called photons (see How Light Works for details).