Puffy eyes in children can be caused by physiologic or pathologic factors, and common pathologic factors include blepharitis, eye allergies, and kidney disease. 1. Physiological factors: If children use their eyes for a long time, stay up late or cry, etc., which affects the blood circulation of the eyes, it can cause children to have puffy eyes. Children need to rest their eyes more often and change their bad lifestyle, which can relieve puffiness. 2. Pathological factors (1) Blepharitis: Blepharitis refers to suppurative inflammation of the eyelid glands, mainly caused by staphylococcus and other bacterial infections, the patient may have localized redness, swelling, pain and other symptoms, and when it spreads to the lower eyelids, the patient may have puffy bags under the eyes. (2) Eye allergy: after contacting pollen, hair and other allergens, allergy such as allergic conjunctivitis can occur in allergic children, and children can have eyelid swelling, accompanied by itchy eyes and other uncomfortable symptoms. (3) Kidney disease: Children with kidney disease such as glomerulonephritis have water and sodium retention due to a decrease in glomerular filtration rate, which, coupled with the thin skin of the eyes and the looseness of the surrounding tissues, leads to the accumulation of water in the local area, resulting in puffy bags under the eyes. It is recommended that children with significant eyelid swelling and other discomforts should be seen promptly for evaluation of their condition and treatment as prescribed by their doctor.