Lower respiratory tract infections affect the airways and lungs. Common infections of the lower respiratory tract include bronchitis (infection of the airways), acute exacerbation of chronic bronchitis, and pneumonia (infection of the lungs).⁵ The main symptom of this type of infection is a cough. Other possible symptoms include a tight feeling in the chest, an increased rate of breathing, breathlessness, wheezing, and fever.⁶
Many lower respiratory tract infections are viral and contagious because of the way the virus is transmitted (e.g. droplet from a cough). Bacterial infections can also develop during the course of the viral infection.⁷