Eyelid swelling may be caused by non-disease factors such as drinking too much water, or it may be caused by eye diseases or systemic diseases. 1. Non-disease factors: sleeping too late, drinking too much water before going to bed, and loose eyelid skin may cause eyelid swelling. 2.Diseases (1)Ocular diseases: Inflammation of the eyelids (e.g., blepharitis, blepharocysts), conjunctivitis, orbital cellulitis, eyelid or lacrimal gland swelling and other ocular diseases may cause patients to have swollen eyelids. (2) Systemic diseases: Patients with systemic diseases such as kidney disease (e.g. glomerulonephritis, nephrotic syndrome), heart disease (e.g. cardiac insufficiency), autoimmune disease (e.g. systemic lupus erythematosus) and other systemic diseases may experience symptoms of swollen eyelids. After ruling out non-disease factors, it is recommended to go to the hospital to clarify the cause of the disease and follow the doctor’s instructions for treatment.