Swelling of the upper eyelid with pain in the patient’s eyes may be caused by trauma, blepharitis, acute dacryoadenitis and other factors. 1. Trauma: If the patient accidentally bumps into the eye, it may cause soft tissue damage, which leads to the symptoms of congestion, swelling and pain in the upper eyelid. 2. Blepharitis: If the patient’s eyelid glands are infected by pathogenic bacteria such as Staphylococcus epidermidis, it may cause inflammation of the eyelids, and under the stimulation of inflammation, it may lead to redness, swelling, heat and pain in the eyelids and other uncomfortable symptoms. 3. Acute dacryoadenitis: Acute dacryoadenitis can be caused by bacterial infections such as Staphylococcus aureus or viral infections such as adenoviruses, which can lead to redness, swelling, and pain on the outside of the eyelid. It is recommended that patients with significant eyelid swelling and pain seek medical attention to evaluate their condition and follow doctor’s instructions.