Doctors generally aren't trained in systemic level thinking, probably because given how complex the body is any such broad connections can only be "intuitive" rather than rigorous, more an art than a science.

This is probably the only reason why "naturopaths" and other "holistic" doctors are still in business, because they'll actually bother to consider a broader picture of a symptom as hinting at some structural imbalance rather than solely treating the symptom as a localized issue to resolve.