The immune system is a very powerful system, but it?s not indestructible. It has many external and internal enemies. For example, are you under a lot of stress? Do you take medications for lowering your cholesterol, or blood pressure, or to control other long term conditions? Are you using your cell phone extensively? Do you live or work next to a cell phone antenna? Were you exposed to UV or X-Ray radiation? Did you pass the age of 40? Stress, medications, radiation (UV, x-Ray, cell phone, etc.), and aging, all decrease the efficiency of the immune system.