The overconsumption of longan leads to the attack of "longan disease". The main symptoms are: diarrhea, nosebleeds, mouth ulcers, inflammation of the oral mucosa, constipation and so on.

Longan is a nutritious and appetizing fruit, but it is easy to get "hot" at the same time. Therefore, the consumption of such fruits should not be too much, especially children, the elderly and suffering from chronic tonsillitis, pharyngitis, "weak fire", constipation, diabetes and other diseases, should not eat or eat less longan and other "fire" type of fruit. Without such a disease, the public, the number of day time consumption of longan should be controlled at about 4 two, not more than 6 two per day at most.