Colds usually do not have the sequelae of leg weakness. The appearance of leg weakness in the pre-cold stage or the late stage of the cold may be related to fever, lack of energy and higher loss of body fluids. 1. Fever: After the virus invades the human body, the immune cells of the human body will produce inflammatory factors while fighting against the virus, which can lead to abnormalities in the thermoregulatory center and cause fever. Fever can lead to symptoms such as weakness of the limbs and muscle aches. 2. Insufficient energy: during a cold, poor appetite and indigestion of food can lead to unabsorbed nutrients and insufficient energy, thus leading to leg weakness. 3. Loss of body fluids: Fever can cause sweating, and poor appetite can lead to less water intake, resulting in more loss of body fluids, which can also lead to leg weakness. Weakness can also be caused by other illnesses and may not be entirely related to colds. If the symptoms persist or worsen, it is recommended to seek medical advice to identify the cause of the problem and treat it. During cold and flu, it is recommended to drink more water, eat a moderate amount of fruits and vegetables to replenish the nutrients needed by the human body and promote the recovery of the disease.