What are respiratory tract infections?

Infections of the respiratory tract are the main reason people visit their family doctor, and they are one of the most common reasons people miss work or school. While adults typically suffer through one to three of these infections each year, children tend to get between two and seven. Most respiratory infections get better on their own, but small babies, the elderly, and people with underlying illnesses can be more vulnerable to the effects of infection.

The respiratory tract is divided in two: the upper and the lower respiratory tract. Upper respiratory tract infections include the common cold (rhinitis or inflammation of the nasal mucosa), sore throat (pharyngitis), tonsillitis, sinusitis, and laryngitis (inflammation of the voice box or larynx). Lower respiratory infections include bronchitis and pneumonia. While bronchitis refers to infection of the big air passages leading to the lungs, pneumonia is infection in the smaller tubes and air sacs, called alveoli.

Most respiratory infections are caused by viruses, which are spread from person to person. There are over 200 viruses that can get you coughing and sneezing! Less frequently, infections are caused by bacteria; for example, pneumonia is usually caused by streptococcus pneumoniae bacteria [source: NHS Clinical Knowledge Summaries]. Influenza, or the flu, is a virus that can cause infection of both the upper and lower respiratory tract.

If you have an upper respiratory tract infection, you will likely be coughing, sneezing, headachy, have a stuffy or runny nose, a sore throat, and lots of muscle aches and pains. A lower respiratory tract infection might have you coughing up phlegm, wheezing, having a tight feeling in your chest, fever and chills, a sore throat, difficulty catching your breath, and muscle aches. Most respiratory infections are self-limiting and get better on their own. Nonsteroidal anti-inflammatory painkillers, fluids, and rest are usually sufficient. Antibiotics are not usually recommended, except in the case of bacterial pneumonia. There are also vaccines available to combat some of the viruses and bacteria that cause respiratory infections, like the flu vaccine or the pneumococcal vaccine.