Fluid accumulation in the leg is mostly due to cold or trauma, and in some cases it is due to synovitis. If the amount of fluid is large, conservative treatment is generally ineffective and requires puncture to extract the fluid; if the amount of fluid is small, conservative treatment can be carried out, such as rest, keeping warm, and soaking the feet in hot water more often to promote local blood circulation, which can make the fluid absorbed. You can also go to the hospital for treatment such as baking electricity and polarized light, which are also useful for the absorption of effusion. In general, the effusion will be completely absorbed in about 2 months, but if there is a disease such as synovitis, the effusion is still prone to recur in cold and wet environment or strain, so pay attention to regular review can be.