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.
X-rays also aid in the treatment of medical patients who have cancer. They can kill the bad cells so that they cannot continue to divide and spread. X-rays can also be used to kill bacteria that causes food to spoil. This is what was used to preserve the food that the astronauts ate while on the moon and in space.