Swelling of the upper eyelid may be caused by poor sleep, mosquito bites, blepharitis and other reasons. 1. Poor sleep: patients who often stay up too late or sleep on a pillow too low, resulting in the concentration of body fluids in the eyes, there will be symptoms of swelling of the upper eyelid, generally no special treatment, improve work and rest, avoid staying up too late can be. 2. Mosquito bites: swollen upper eyelids can be caused by mosquito bites, mosquito bites, mosquito saliva in the acidic substances to irritate the skin of the eyes, can trigger allergies and redness, but also with itching, pain and other symptoms. 3. Blepharitis: Swelling of the upper eyelid may be caused by bacterial infection of the inflammation of the blepharoplasty gland, the patient may also be accompanied by tenderness, pain is more obvious when blinking, and abscesses may be formed in the later stage. If the swelling of the upper eyelid does not improve after a long period of rest or is accompanied by other discomforts such as eye pain, it is recommended to go to the hospital as soon as possible and follow the doctor’s instructions for treatment.