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.
Read more in How X-rays Work. Gamma rays: Gamma rays have the most energy and shortest wavelength of the entire spectrum. Nuclear explosions and radioactive atoms generate these rays. Gamma rays can kill living cells, and medical professionals sometimes use them to destroy cancerous cells.