Puffy eyelids in children may be related to physiological factors or may be caused by allergic reactions, conjunctivitis, kidney disease, and so on. 1. Physiological factors: If children cry excessively for a long time, drink too much water at night, or sleep with their heads in a low position, they may have swollen eyelids. Usually no special treatment is needed and it can be relieved after rest. 2. Allergic reaction: children with allergic constitution may have eye allergy after coming into contact with allergens such as dust mite, pollen, etc., and the children may suffer from eyelid swelling and other uncomfortable symptoms, accompanied by obvious itching, pain and other discomforts. 3. Conjunctivitis: Some children often rub their eyes with dirty hands due to unhygienic eye use, which may lead to conjunctival infection and conjunctivitis, and under the stimulation of inflammation, children may have swollen eyelids, which may be accompanied by tearing and frequent blinking. 4. Kidney diseases: Children with kidney diseases such as acute glomerulonephritis may have swollen eyelids and lower limb edema due to the weakened glomerular filtration capacity, which makes it difficult to expel water from the body and causes fluid retention in the body. It is recommended that children with significant eyelid edema should be seen promptly for evaluation of their condition and treatment in accordance with medical advice.