The inexplicable redness and swelling of the eyelids may be caused by blepharitis, mosquito bites, allergies and other reasons. 1. Blepharitis: due to the lack of attention to eye hygiene or excessive eye use and other reasons, leading to a decline in the resistance of the eye, so that the virus invades and infects the eye, causing blepharitis, due to the repeated stimulation of inflammation, so that the conjunctival tissues of the eye localized congestion and swelling, which in turn appeared in the eyelids of the situation of redness and swelling. 2. Mosquito bites: generally due to the eyes accidentally mosquito bites, due to mosquitoes have certain toxins, after mosquito bites, toxins will be injected into the eyelid tissues, resulting in localized swelling of the eyelid tissues, and then the phenomenon of eyelid redness and swelling. 3. Allergy: due to the abuse of cosmetics or medicines in the eyes and other reasons, resulting in eyelid stimulation, causing allergies, due to allergies, so that the eye tissues itchy, and localized redness and swelling, which in turn cause eyelid redness and swelling of the situation. Eyelids inexplicably red, may also be associated with blepharitis, granuloma and other diseases, if the phenomenon of inexplicable eyelid redness and swelling, you should promptly go to the hospital for examination, follow the doctor’s instructions for treatment.