Viruses are extremely difficult to kill because they are much smaller than bacteria and like to hide in secluded places. Many lay dormant and only surface during stressful conditions. This is why some people will experience bouts of fatigue after going through an emotional experience. Any patient who suffers from fatigue is always checked for viral infections. One advantage to the Asyra is that these viruses can be identified. Once identified a remedy can be made to kill the virus.