Just like a virus creating a problem to the personal computer, our negative thoughts, emotions, words, situations, challenges, comments, images & the like many things will act as a virus and will affect our mind & brain (The Biggest Sophisticated Computer) and our whole physical and mental functioning become deranged or corrupted & will present as various physical & mental diseases and illness. Usually, the physical symptoms are manifested very gradually and will be noticed only when it becomes an emergency. When we say the virus, it is a negative thought or a script which was registered in our mind & brain at some point of time, knowingly or unknowingly.