Cat stress reaction refers to the physical and emotional discomfort caused by cats after being stimulated by the outside world, such as vomiting, rapid heartbeat, elevated blood pressure, loss of appetite and other symptoms. Generally, cats will have stress reactions when they change homes, change cat food, or are frightened. At this time, it is best to hold the cat or let the cat stay in the room by itself, and it will recover on its own in about a day or two.