There is a cruel case. During World War II, the Nazis did a living experiment: they blindfolded a prisoner of war, stretched out their hands, and then told him to bleed until the blood ran out. Of course, they cut his wrist with an ice knife, but there was no real bleeding, and they opened the water pipe prepared in advance and let the water drip in the pipe below, as if there was really blood dripping. Two hours later, people found him dead, the cause of death was excessive blood loss.

This is the same as you said. When people are convinced that something is happening in the body, the body itself will have a stress reaction. This reaction is a kind of regulation of human endocrine system, so the phenomenon is consistent with the real situation.

In the process of hypnosis, when you input instructions, he is completely convinced, so this phenomenon will occur. And there are many related cases. This is also an important reason why hypnosis can cure diseases.