Upper eyelid swelling can be caused by lack of sleep, drinking too much water before going to bed, insect bites, blepharitis, kidney failure as well as heart failure. 1. Physiological factors: Lack of sleep can lead to irregular blood flow inside the eyelids and the surrounding blood vessels, and the water in the blood leaks out of the blood vessels and accumulates in the eyelids, causing upper eyelid swelling. If patients drink too much water before going to bed and urinate less at night, the water in the body accumulates in the eyelids, which can also cause upper eyelid swelling. 2. Mosquito bites: When the weather is hot, there are many mosquitoes that bite the upper eyelid, causing localized inflammation and swelling of the upper eyelid. 3. Blepharitis: Bacterial infection of the upper eyelid’s blepharoplasty gland causes blepharitis, which generates cysts and causes upper eyelid swelling. 4. Kidney failure: Kidney failure leads to a decrease in the kidney’s ability to filter blood, resulting in sodium and water retention in the body, causing upper eyelid swelling. 5. Heart Failure: Heart failure leads to a decrease in the heart’s ability to pump blood, causing water and sodium retention in the body, resulting in upper eyelid swelling. It is recommended that patients with severe eyelid edema consult a doctor in time to assess their condition and follow the doctor’s instructions for treatment.