Swelling of hands and feet may be a physiological phenomenon caused by prolonged soaking in water, or it may be caused by hypoproteinemia, kidney disease, or heart disease. 1. Physiological phenomenon: If the hands and feet are soaked in water at the same time, such as swimming or bathing, the skin will absorb too much water and swell, resulting in swelling of the hands and feet. 2. Pathological factors (1) Hypoproteinemia: Hypoproteinemia usually refers to the plasma albumin content of the human body is lower than normal, which will lead to a decrease in plasma osmotic pressure, thus leading to edema and swelling of the hands and feet. (2) renal disease: if the patient has renal disease, it will cause water and sodium retention, increased capillary permeability, decreased plasma osmotic pressure, which will lead to the phenomenon of hand and foot swelling. (3) Heart disease: If the patient has heart disease, it will lead to decreased cardiac output, decreased glomerular filtration rate, and will also lead to swelling and bloating. There are many reasons for swelling of the hands and feet, and it is recommended that patients go to the hospital in time to find out the cause and follow the doctor’s instructions for treatment.