There are many causes of limb infections, for example, when patients with diabetes often develop infections secondary to small injuries to the extremities, especially the lower extremities. For example, mosquito bites or accidental bumps often lead to lymphangitis or dengue, cellulitis, etc. in the lower extremities. The infecting bacteria are usually Staphylococcus aureus or Streptococcus hemolyticus, and sometimes foot infection can also be secondary to limb infection, which is usually a fungal infection, so limb infection mostly comes from bacteria or viruses. If a patient with normal immunity has a bump or trauma, it is difficult to cause infection because the immune barrier of the body includes the skin and mucous membranes, and we can usually exercise more to strengthen the body’s immunity.