The causes of enlarged labia minora include normal development, vaginitis, allergy, etc. 1. Normal development: After women enter puberty, affected by hormone levels, the labia majora and minora will appear darker and thicker, which is a normal physiological development. 2. Vulvovaginitis: due to unclean personal hygiene or poor sexual history, resulting in vulvar infections such as bacteria, viruses, etc., localized swelling, pain, accompanied by increased secretion, the labia major and minora enlargement of the performance. 3. Allergy: women who are allergic to semen or intolerant to the use of sanitary napkins may suffer from allergic symptoms such as swelling and enlargement of the vulva, itching, pain, burning, and so on, and in severe cases, they may also suffer from generalized urticaria and respiratory difficulties. Clinical situation of sudden enlargement of labia minora, should promptly consult a doctor, under the guidance of the examination, to clarify the cause of the disease, and active treatment.