If you bring your cat to the veterinarians office because hes vomiting, does the doctor simply perform a clinical exam followed by x-rays and blood work, or does she add in some questions that help her learn the story of the cats life? For instance, a vet might ask, Has anything changed lately? Have you moved, or has someone moved into or out of your household? Has there been a divorce or some other difficult event? That way, the doctor may find out that the cat is stressed, perhaps because he is sensing your own stress, and that is what is making him throw up.