The common causes of edema in the arm are as follows: 1. upper limb trauma: such as muscle injury and fracture dislocation can cause local bleeding and severe edema, accompanied by pain and restricted movement. 2. skin diseases: patients with diseases such as contact dermatitis may have acute allergic edema. 3. upper limb vascular disease: such as deep vein thrombosis, resulting in venous return obstruction, can also cause edema in the arm, accompanied by generalized numbness. 4. 4.Medical diseases: such as heart disease, malignant tumor, etc., hypoproteinemia and malnutrition may cause edema in the arms, accompanied by general weakness. If edema occurs in the arm, the cause should be clearly identified first, and the corresponding treatment method should be selected according to the cause, which can bring about rapid relief of clinical symptoms.