Parasites are organisms that survive by stealing nutrients from their hosts. Whenever the story about these microorganisms is told, many people freak out. It sounds like a story that exists only in sci-fi movies. Some parasites can live without causing any symptoms in their host. But, others trigger severe illnesses. The illnesses occur when the parasites reproduce, grow, or interfere with an organ system that can make one ill.  Without saying much, here are five things that you should know about parasites.   1. How common are parasites     Many individuals still don’t believe that they may have parasites in their system. The truth is, parasites are a lot more common in…