The primary sympton of a lung or lower respiratory infection is a product cough with discolord sputum usually yellow, green, or brown. This could be bronchitis, pneumonia, etc. For many of us, this can start as a sinus infection then move down into the airways. Whatever you do, don't ignore it. Have a doctor diagnose whether it is viral or bacterial. If bacterial, then antibiotics are described. The challenge is which one. There is a plethora of antibiotics to choose from for this type of infection. Get that infection cured !!!