If one face is large and the other is small, you need to go to the hospital for examination, the specific reasons are as follows: First, the most common factor is the infectious factor, of which bacterial infection is particularly significant, the capillary-rich area in the face will be infected, the infection of bacteria will appear local cellulitis, in the infected side of the face will appear large face, and the other side of the face is small. The side with large amount of infection will also have redness, swelling, heat, pain, peripheral joint disorder, or discharge exudate and other conditions appear. Second, if infected by the virus, trigeminal neuralgia and facial neuritis will appear, because when facial neuritis and trigeminal neuralgia occur, there will be twitching and jerking of the facial nerve on the infected side, and the infected side will have a small face, while the opposite side will have a large face. Third, in peripheral connective tissue diseases, the above clinical symptoms will also appear, such as dermatomyositis or dry syndrome, etc., and the two parts of the face will also appear asymmetric in size.