Cold with leg weakness may be caused by viral infection, lack of oxygen or prolonged inactivity. 1. Viral infection: Colds are caused by viral infection, which may lead to different degrees of fever, sneezing, nasal congestion, fatigue, muscle aches and pains, and so on, and therefore patients may have colds with leg weakness. 2. Lack of oxygen: patients who have a cold may suffer from nasal congestion, which in the long run may cause lack of oxygen in the body and muscle weakness, and may also suffer from leg weakness. 3. Prolonged inactivity: During the cold period, the patient’s physical condition is poor, and prolonged inactivity leads to poor physical endurance and muscle atrophy, which may cause leg weakness. Cold with leg weakness should also pay attention to clarify whether the combination of other neuromuscular diseases, it is recommended to go to the hospital in time to improve the relevant laboratory tests for evaluation, so as to avoid delaying the condition.