Research evidence suggests that each part of the body communicates with the other, an imbalance in one part having a knock on negative impact on another body part.
To demonstrate my thinking, I use the metaphor of a bike. You might need to oil the chain, pump up the tyres and raise the saddle for maximum comfort and bike efficiency. If you only pump up the tyres, and don't look after the other parts of the bike, you will not have an easy ride.
To be healthy we need strength, flexibility, balance, a sense of purpose and to know our own values … it's important to have balance in both body and mind and to look after our bodies for optimal performance.
REF: https://www.hypnotherapists.org.uk/8159/links-found-between-stress-and-autoimmune-conditions/