7-Mild infection of the upper respiratory system
It covers the nasal cavities, trachea, larynx, and pharynx (throat). It comes with very similar symptoms of the common cold: increased production of mucus (runny nose) and inflammation of the lining of the nose (difficult breathing and causes nasal congestion). Sometimes comes with sneezing (by nose irritation ) and cough (by the increase of mucus that drips in the throat). That is why it is usual with polio patients to be diagnosed initially with the flu.