Which branch of psychology explores the relationship between psychological factors and physical ailments or disease?

I believe the answer is: Health Psychology

Health Psychology studies how behaviours and way thinking could affect the overall health condition of individuals. This field view that the behaviours, emotion, or thought could triggers a certain substance from being released/produced in our body, that give a certain benefit or negative impacts to our body.

european feudalism was a combination of legal and military customs in medieval europe that flourished between the 9th and 15th centuries. broadly defined, it was a way of structuring society around relationships derived from the holding of land in exchange for service or labour.

japanese feudalism. the era of feudalism in japan took place from the 12th through 19th centuries. during that period local rulers, either powerful families or military warlords, dominated the land, while the emperor was merely a figurehead and not a significant political presence.