Upper respiratory tract infections • Patient presents with sneezing, sore throat, headache, cough, runny nose and body ache with fever. • Diseases include common cold (head cold), the mild flu, tonsillitis, laryngitis, and sinus infection Lower respiratory tract infections • Patients present with severe cough that may produce mucus, shortness of breath, chest tightness, and wheezing when exhaling • Diseases include viral infections like the severe flu or bacterial infections like tuberculosis