Possible reasons for the labia minora not being the same size on both sides include: developmental deformity of the labia, trauma, and genital infection. 1. Developmental deformities of the labia minora: the different sizes of the labia minora on both sides may be caused by deformities during development. 2. Trauma: If the labia minora suffer from irritation, trauma, etc., it will also make the labia minora different sizes, which should be observed more carefully in daily life, and usually can be recovered by itself. 3. Genital infection: If the genitals are invaded by pathogens, the labia minora may appear to be of different sizes in order to protect the vagina from germs. If the labia minora are not the same size on both sides, you should go to the hospital in time to clarify the cause and treat it under the doctor’s guidance.