Swelling of both hands can be caused by physiological and pathological reasons, including overuse of hands, vascular occlusion of upper limbs, hypoproteinemia, renal insufficiency, etc. 1. Physiological causes: Swelling of hands may be caused by excessive use of hands, such as long time playing with cell phone, computer, etc., which leads to poor blood circulation in both hands and causes swelling of hands. 2. Pathological causes (1) If the blood vessels of both upper limbs are occluded, poor blood circulation can cause swelling of both hands, which can not be relieved by changing postures, and can be identified by checking the vascular ultrasound of both upper limbs. (2) Hypoproteinemia causes intravascular albumin insufficiency, colloid osmotic pressure decreases, water extravasation to peripheral tissues, which can cause edema in all parts of the body, including edema of hands. It can be improved by supplementing albumin, and checking the liver function can reveal the decrease of albumin. (3) Patients with renal insufficiency may suffer from decreased renal drainage capacity and sodium retention, causing generalized edema, and in severe cases, edema of both hands, which can be detected by checking renal function and renal ultrasound. Swelling of both hands can also be seen in other causes such as rheumatoid arthritis, vasculitis, etc., found that swelling of both hands need to be timely hospital consultation, identify the causes, and target treatment.