Advantages and disadvantages

X-rays are definitely one of the most renowned breakthroughs in medical, and scientific histories. However, as nothing in the world is perfect, there are some side effects to using the X-ray.

X-rays can still be harmful. In the early days of X-ray science, doctors and patients would be exposed to the beams for long periods of time and they eventually developed radiation illnesses; this is when the doctors knew something was wrong. 
The problem is that X-rays are a form of ionizing radiation. When normal light hits an atom, it can't change the atom in any profound way. But when an X-ray hits an atom, it can knock electrons off the atom to create an ion, an electrically-charged atom. The ions will knock other electrons around and form even more electrically-charged atoms.
An ion can lead to unnatural chemical reactions inside cells. Among other things, the charge can break DNA chains. These cells will either die or the DNA strand will become mutated. If enough cells die, then the body will contract various diseases. If the DNA mutates, a cell may become cancerous, and this cancer shall spread. If the mutation is in a sperm or an egg cell, it may lead to birth defects. All of these risks have made doctors use X-rays sparingly today. 
Even with these risks, X-ray scanning is still beneficial because it is safer than surgery. X-ray machines are an invaluable tool in medicine and a plus in security and scientific research. They are truly one of the most useful inventions ever.