Swelling of the hand without obvious trauma is common in the following three cases. The swelling may occur due to the repeated contraction of the limb muscles, which act as a venous pump for the return of deep venous blood, and the hand being in a drooping position for a long time without activity, which may lead to obstruction of venous blood return. Second, it may be caused by the formation of venous thrombosis in the upper limbs, for example, patients who hold clutches for a long time may produce thrombosis in the axillary vein and lead to swelling of the hand. Third, the swelling may be caused by soft tissue infection, which may manifest as local redness, swelling, heat and pain.