The main causes of swollen hands and feet in patients suffering from systemic diseases and hypoproteinemia are as follows: 1. Systemic diseases: If both hands and both feet become swollen, it usually indicates that the patient has systemic diseases, such as heart insufficiency and heart failure resulting in reduced ejection fraction of the heart, tissue fluid will increase and the amount of blood returned to the heart will decrease, and swollen hands and feet will occur. 2. Hypoproteinemia. If the hypoproteinemia caused by liver insufficiency, the tissue fluid will also increase due to the decrease of human colloid osmotic pressure, which can penetrate into the subcutaneous tissue, resulting in swollen hands and feet. In addition, proteinuria and sodium-water retention caused by renal insufficiency can also lead to hypoproteinemia and an increase in body fluids, which can lead to a corresponding increase in tissue fluids, resulting in swollen hands and feet. In addition, if the hand and foot are swollen on the same side, it usually indicates that it is caused by congenital vascular malformation.