Sudden swelling of the left eye bag is generally not uveitis, commonly due to mosquito bites, inflammatory reactions, etc. Further examination is needed to confirm the diagnosis. The sudden swelling of the left eye bag with itching symptoms may be caused by mosquito bites, which can be wiped with soap and water, flower lotion, cool oil, etc., which has the effect of stopping itching. In addition, if the left eye bag appears significantly red and swollen with pressure pain, it may also be due to inflammation, such as blepharitis or eyelid boils. Patients with uremia usually show generalized edema due to impaired water and electrolyte metabolism, with morning eyelid edema being more common, usually in both eyelids at the same time, while swelling of the left eyebag alone is less likely. If unsure, patients can visit the nephrology and dermatology departments of the hospital to clarify the specific cause. Patients should not rub their hands when the sudden swelling of the left eye bag occurs, because if the patient is caused by inflammation, it may lead to the spread of inflammation after being squeezed. In addition, patients should temporarily avoid eating seafood as well as spicy and irritating foods.