Uremia after dialysis arm bags may be vascular pressure difference, tumor-like lesions, allergies and other causes. 1. Vascular pressure difference: dialysis patients generally need vascular fistula, connecting arteries and veins, the pressure of the arteries is much greater than the pressure of the veins, there may be venous blood vessels bulging, after dialysis may produce arm pouch. 2. Tumor-like lesions: blood pressure measurement on the arm with fistula or repeated puncture at the point of dialysis may cause tumor-like lesions in the veins, which are manifested as arm pouching. 3. Allergy: when the patient is allergic to the dialysis solution or certain components in the dialysis tubing, arm pouching after dialysis may also occur. Uremic dialysis arm bags may also be seen in other reasons, it is recommended that patients go to the regular hospital in time, after the cause of the disease is clear, under the guidance of the doctor to the targeted treatment or therapy.