Facial edema may be caused by allergic reaction, thyroid disease, connective tissue disease, renal edema and other factors. 1. Allergic reaction: contact, inhalation or ingestion of allergens by allergic patients may cause an allergic reaction, resulting in facial edema, usually accompanied by urticaria-like manifestations. It is recommended to detach from the allergens and take antihistamines such as loratadine and cetirizine if necessary. 2. Thyroid disorders: Thyroid disorders include hyperthyroidism and hypothyroidism, such as hypothyroidism, which may lead to mucous edema. Hyperthyroidism may cause hyperthyroid heart disease when it is more serious, and the edema caused at this time is a characteristic edema, mostly depressed edema. 3. Connective tissue diseases: Connective tissue diseases, such as systemic lupus erythematosus and dermatomyositis, may cause facial edema. Systemic lupus erythematosus, may affect the heart, resulting in decreased cardiac function. When the patient has heart failure, it may cause edema. 4. Nephrotic edema: patients with nephrotic syndrome may have the manifestation of generalized edema, and facial edema is more obvious. In renal edema, the degree of edema is mostly mild or moderate, and may be accompanied by elevated blood pressure. In addition to this, eye diseases, oral diseases, nasal diseases, etc., may also lead to facial edema. It is recommended not to use medication blindly, but to actively seek medical attention to clarify the cause and follow the doctor’s instructions.