Children’s lower eye bags suddenly swollen, may be infectious factors, allergic causes, sleep deprivation and other causes. 1. Infectious factors: bacteria, Chlamydia trachomatis, and other pathogenic bacteria infection, resulting in patients with eye tissue infection, the patient may appear eye congestion, swelling, but also increased secretions, photophobia, tearing and other discomforts, the child may appear suddenly swollen bags under the eyes performance. 2. Allergic causes: allergic children exposed to pollen, hair, etc., allergic conjunctivitis and other ocular allergic diseases, resulting in children with swollen bags under the eyes, can also be accompanied by itching and other symptoms of discomfort. 3. Lack of sleep: If the child stays up late, tired, lack of sleep or too much exposure to electronic products, it may also lead to sudden swelling of the lower eye bags, but usually the swelling is not obvious. It is recommended that patients with obvious swollen bags under the eyes consult a doctor in time to assess their condition and follow the doctor’s instructions for treatment.