Eighty-year-olds with a swollen foot may be caused by wrestling sprains, but also may be caused by dengue, lower extremity deep vein thrombosis and other diseases. 1. foot sprain: eighty-year-olds walk inconveniently, easy to fall, then if the sprained ankle, can lead to a swollen foot, this is due to violence damage to the joints and surrounding ligaments, resulting in localized congestion and edema, the treatment should be the first ice, pressure, but also pay attention to rest. 2. dengue: dengue is a type b hemolytic streptococcus invasive infection caused by the skin lymphatic network of acute non-suppurative inflammation, if it occurs in the unilateral lower limbs, there can be more than eighty years old a foot swelling symptoms, treatment can be treated with penicillin and other medications, but also can be used locally magnesium sulfate, ibuprofen, etc. Cold compresses. 3. Lower extremity deep vein thrombosis: the elderly due to a variety of reasons lead to inconvenient movement or high blood coagulation, unilateral lower extremity formation of deep vein thrombosis, due to unilateral blood reflux is not smooth, can also lead to the symptoms of the eighty-something year old man with a swollen foot, the treatment can be in the lower vena cava vein to place a filter, but also the use of warfarin, urokinase, and other drugs for anticoagulation, thrombolytic therapy. In addition to the above diseases, other diseases can also lead to the symptoms of swelling of one foot in the eighty-something old man, should be timely medical treatment, so as not to delay the condition.