Swollen labia minora and majora. why so much thicker than the normal size?

Seek evaluation: Bilateral enlargement of labia minor and major is highly unusual and suggests an allergic reaction or lymphatic venous obstruction. See your gynecologist for this.

Multiple causes: Thick or swollen labia are usually caused by infections or problems with the skin. Infections can be as simple as a yeast infection, a sexually transmitted disease or a walled off infection. Skin problems can be simple like eczema or an immune problem like psoriasis. You should see your doctor to get tested.