If you're getting enough sleep each night- it can be caused by allergies--but yet allergies are a symptom of having parasites-- especially roundworms- (which often go unnoticed in a person until they do a month or two or longer of parasite cleanses)
So , yeah , your doctor may be right- but it can go beyond allergies. Allergies are yet one more symptom and not the root of the problem.
Many people who have rid themselves of an intestinal parasite situation and have done Liver Flushes
have found they dont even get hayfever anymore.