Eyelid edema is clinically common and occurs easily due to the laxity of the eyelid skin. There is physiologic eyelid edema and pathologic eyelid edema. Some are due to ocular disease and some are due to systemic disease. Physiologic eyelid edema: Physiologic eyelid edema is usually due to lack of sleep at night, excessive sleep time, or because the pillow is too low for nighttime sleep, which affects facial blood return, and in some women before menstruation. This type of eyelid edema is mostly seen in healthy people and has little effect on the body and often subsides naturally. 2. Pathological eyelid edema: (1) Eyelid inflammation: Blepharitis: There is flushing of the eyelid skin, swelling, pain, limited tenderness, hard nodules to touch, the roots of the eyelashes, and a few days later pus spots on the skin near the lid margin or on the conjunctival surface of the lid. Blepharitis: Mostly involves both eyes, with flushing and slight swelling of the eyelid margin, irritation, burning, itching, some flaking of the skin, and some erosion of the eyelid margin. Eyelid abscesses: are more commonly seen as a result of the development of blepharitis. The eyelid and bulbar conjunctiva are highly edematous, and the preauricular or submandibular lymph nodes are enlarged and pus-forming with a fluctuating sensation on palpation. Cellulitis of the eyelid or orbit: Eyelid erythema, fever and erythema, tenderness, and in severe cases, inability to open the eyelid due to high eyelid edema and increased skin tension and tightness. In addition to eyelid edema, these inflammatory conditions have localized redness, heat, and pain, and some have significant pressure pain. Allergic inflammation of the eyelids (contact or sun exposure, insect bites) This type of eyelid edema has a sudden onset, bright red eyelids, significant swelling, or even inability to open the eyes, itchy skin, no tenderness, exposure to allergens and recent topical eye or eyelid skin medications, or a history of hair dye. Electrophthalmic ophthalmia: a common radiation injury, most often seen in metal welders or film workers under mercury lamps, working without protective eyewear, due to the cumulative effect of ultraviolet radiation exposure, the onset of the disease can be accumulated to more than 15 minutes a day, incubation period of 6-8h, mostly in the twilight or midnight, accompanied by significant pain, photophobia, lacrimation blepharospasm, eyelid and conjunctival edema, positive corneal fluorescein staining. Eyelid and orbital contusions: history of significant trauma. (2) Periocular lesions: Acute lacrimal sacculitis: mostly acute attacks of chronic lacrimal sacculitis with redness, swelling, heat, and pain in the lacrimal sac area, swelling spreading to the nasal root, and pain radiating to the teeth and frontal area. Acute lacrimal glanditis: monocular onset, eye pain, tearing, localized pressure pain, redness and swelling of the lid margin in the outer 1/3 of the upper lid, ptosis (inflammation), making the upper lid S-shaped, high edema of the eyelid, congestion and edema of the bulbar conjunctiva over the outer surface, a mass can be found in the upper part of the orbit, mild protrusion and downward displacement of the eyeball, may be accompanied by fever. (3) Acute conjunctivitis: eyelid swelling, conjunctival congestion, and increased secretions. Endophthalmitis: sudden progressive vision loss, ocular redness, marked ocular pain, eyelid edema, conjunctival edema, and anterior pus accumulation. Spongy sinus thrombosis: swelling of the eyelids, protrusion of the eyeballs, varying degrees of mild paralysis in the innervated areas of the III, IV, and VI cerebral nerves, and ocular motility disorders.Graves’ disease: early stages may be asymptomatic. Uncontrolled disease may present with direct eye gaze, upper eyelid contracture or upper eyelid not following down when the eye looks down. With further progression, there may be soft tissue symptoms, such as subjective excessive tearing, foreign body sensation in the eye, ocular discomfort, photophobia, etc., and the appearance of conjunctival and eyelid edema and conjunctival congestion. (3) Non-inflammatory swelling: Mostly without localized redness, swelling, heat, or pain. It is a rare eyelid disorder characterized by recurrent eyelid edema in adolescents, with thinning of the eyelid skin, loss of elasticity, increased wrinkles, color changes, and can be complicated by clinical manifestations such as lacrimal gland prolapse, ptosis, and shortening of the transverse lid diameter. The early clinical manifestations are recurrent episodes of angioneurotic edema of the upper eyelid skin of unknown origin, which persists for 2 to 3 d and resolves spontaneously, insensitivity to antihistamines and corticosteroids, and the frequency and extent of episodes vary between patients and at different times in the same patient. The lower eyelid is only involved in severe cases, and unilateral onset is rare. Orbital rhabdomyosarcoma: An intraorbital malignant tumor common in childhood, most often occurring within the age of 10 years, rarely in young adults, and occasionally in adults. The tumor is located in the upper orbit, causing the eye to protrude forward and downward, with eyelid edema and bulbar conjunctival edema protruding beyond the lid fissure, similar to orbital cellulitis. Hypothyroidism: The symptoms are usually weakness, coldness, fear of cold, dry and rough skin, sparse and dry hair, brittle and cracked nails, fatigue, drowsiness, poor memory, mental retardation, unresponsiveness, indifferent expression, little speech, hoarseness of speech, slurred speech, pale and waxy face, facial swelling, dull gaze, puffy eyelids, mild anemia, weight gain. Nephrotic edema: In the early stage, only eyelid or facial edema is found when waking up in the morning, but later it may develop into generalized edema. Edema, elevated blood pressure and urinary changes (hematuria, proteinuria and tubuluria) are strong evidence for the diagnosis of nephrogenic edema. Cardiopathic edema: usually a manifestation of right heart failure, occurs first at the site of ptosis, and if facial and eyelid puffiness is present, it is indicative of a severe condition. Idiopathic neurovascular eyelid edema: It is an allergic disease in which the patient often has a history of allergy to medications, foods, or the surrounding environment, with prodromal symptoms prior to onset. The edema of this disease is characterized by sudden onset, painless, hard and elastic limited edema. The edematous skin is pale or waxy and shiny, the edema is slightly concave in the center with no distinct edges, and may occur suddenly on the eyelids with marked, shiny edema. Premenstrual tension syndrome: Edema is a common symptom. Patients often have increased excitability, irritability, irritability, frequent insomnia, headache, sometimes migraine, breast swelling, easy fatigue, and poor concentration of thought. Weight gain of 1 to 2 kg or more, eyelid edema, ankle and hand edema. Most of the above symptoms appear 7 to 14 days before menstruation and subside on their own after the onset of menstruation. In some patients with eyelid edema that is not due to eye disease, it is important to actively look for the cause and treat the primary disease, as only after the primary disease is cured and the systemic disease improves can the eyelid edema gradually subside.