What Causes Fatigue?

Research says there is a minimal impact of genetics on fatigue. But if we look at it through the lens of epigenetics, what's turning genes on and off? There are people that have those gens that don't have fatigue. We need to go a step further back and look out what are the factors some one's life that caused them to develop fatigue? And this all results in an impact on our different bodily systems. For some people, primar y, the impact is on their digestive system. For other people It's more in their immune function. Map out what's been going on with your body since you were five years old. That helps us understand both from a causal point