Swelling and pain in the foot for no reason, this situation is mainly due to two reasons: 1, because the location of the foot itself has old injury or more local calcification, hyperplasia and so on, after walking too much will lead to the accumulation of local metabolic products, increase, especially in the rest and cold state, easy to lead to local easy to appear serious edema, the situation of swelling and pain in the foot for no reason. This situation needs to keep the foot relaxed, rest, and to elevate the position of the foot, and try to exceed the horizontal position of the heart when lying down, so as to effectively promote local inflammation, bruising and metabolites metabolism and absorption, which helps to relieve the symptoms of swelling and pain; 2. It is possible that the location of the foot has suffered from mosquito bites, resulting in local allergy, swelling and pain. This situation can be intravenous dexamethasone injection, anti-inflammatory, anti-allergic treatment, you can also apply dexamethasone acetate cream in the location of the swelling and pain, can also play a certain therapeutic effect. You can also take oral anti-allergy medications such as chlorpheniramine maleate, which can also effectively relieve the symptoms.