Causes of eye edema include physiological factors, acute injury, infectious factors, kidney disease, etc. 1. Physiological factors: sleeping with too low a pillow, drinking a lot of water before going to bed, or resting poorly may lead to temporary eyelid edema, which usually has no other clinical manifestations and can return to normal on its own, without special treatment. 2. Acute injury: when the eyelid area is hit by external force, it can lead to localized damage to the eyes, resulting in symptoms of eye swelling, which may be accompanied by pain, redness and other symptoms. 3. Infectious factors: for example, acute dacryocystitis, acute conjunctivitis, blepharitis, etc., due to the stimulation of inflammatory substances, the eyes may appear swollen, accompanied by dry eyes, tearing, pain, itching and other symptoms. 4. Kidney disease: for example, nephrotic syndrome, glomerulonephritis, etc., water and sodium retention can occur, thus causing symptoms of eye swelling, may also be accompanied by swelling of the lower limbs, proteinuria and other abnormal manifestations. It is recommended that patients with swollen eyes should consult a doctor for examination and treatment in time to avoid delaying their condition after eliminating physiological factors.