Swelling of the left eyelid may be caused by incorrect sleeping position, mosquito bites or eye inflammation, etc. Patients can be treated by physical therapy, medication, etc. The specific treatment is related to the patient’s condition. 1. Incorrect sleeping posture: some patients like to sleep in a prone position, the eye is compressed resulting in local blood circulation disorders, and the left eyelid swelling, generally do not need special treatment, can be relieved after rest. Patients can also apply cold compresses locally on the eyelids to promote the swelling to subside and relieve eye discomfort. 2. Mosquito bites: If the patient’s eyelids are stung by mosquitoes or bees, insect bite dermatitis can be triggered, and the patient can have left eyelid swelling, accompanied by eyelid itching, redness and other symptoms. Patients can apply local cold compresses to relieve eye discomfort, but also the use of tobramycin dexamethasone ophthalmic ointment and other medications as prescribed by the doctor, to promote the swelling to subside, relieve eye discomfort. 3. eye inflammation: if the patient because of bacterial or viral infection, resulting in conjunctivitis, keratitis and other eye inflammation, in the inflammation stimulation, the patient can appear eyelid swelling, can also appear eye congestion, pain and other discomforts, the patient can comply with the doctor’s instructions to use levofloxacin eye drops and other drugs anti-infective treatment, to alleviate the symptoms of discomfort. It is recommended that patients with significant eyelid swelling consult a doctor to assess their condition, follow the doctor’s instructions for treatment, avoid rubbing with the hands, and pay attention to eye hygiene.