Air conditioning blowing knee pain may be due to the normal physiological reaction caused by the low temperature, but also may be cold stimulation of the knee original disease, such as osteoarthritis, knee synovitis exacerbated by the pain. 1. Physiological reaction: the low temperature will make the leg vasoconstriction, insufficient blood supply will lead to muscle spasm, thus causing knee pain. 2. Osteoarthritis: If the patient suffers from osteoarthritis caused by degenerative changes in the knee joint, when subjected to cold stimulation, vasoconstriction will lead to increased inflammation, thus causing pain. 3. Knee synovitis: If the patient has a history of trauma to the knee, or a history of strenuous sports injuries, old injuries have not been fully recovered, may suffer from knee synovitis, in the cold stimulation of blood flow slows down, inflammatory factor precipitation leads to increased inflammation, resulting in pain. If patients suffer from knee pain due to air conditioning, they should stop blowing air conditioning and pay attention to keeping warm, and if the pain cannot be relieved, they should go to the hospital in time for examination and consultation.