Upper Respiratory Tract Infections

Upper respiratory tract infections include conditions such as colds, influenza or flu, sore throat, strep throat and acute bronchitis. These conditions are caused by viruses or bacteria and affect the airways in the nose, ears and throat. Most upper respiratory tract infections are mild and temporary, but some can cause more serious conditions such as pneumonia.

Some of the most common upper respiratory infections include:


The common cold is the most common type of upper respiratory infection. It has been estimated that Americans develop two to four colds per year. Colds can be caused by more than 200 viruses. The first symptoms of a cold usually include a sore throat and stuffy nose. Other symptoms develop gradually and include sneezing, low fever, cough, headache, muscle aches and runny nose. Most colds are harmless and go away within a couple weeks. However, in rare cases, colds can lead to other complications such as sinus or ear infections. Colds can also aggravate asthma.


Influenza, or flu, is caused by a virus. It is an infection in the nose, throat, bronchial tubes and lungs. A sudden onset of the following symptoms is a good indication of flu:

  • Fever above 101
  • Chills
  • Headache
  • Muscle aches
  • Extreme fatigue.
  • For healthy people, flu usually is not dangerous.

However, when flu hits people over 65 or those who have other medical conditions such as diabetes or heart disease, serious complications such as pneumonia can occur.

Sore Throat and Strep Throat
Sore throats that occur with colds are usually mild. People with more severe sore throats may be suffering from strep throat. This usually develops suddenly, and the person may have difficulty swallowing along with a fever. Other symptoms of strep throat can include headache, stomach ache and vomiting. Cold symptoms are usually not present.

Acute Bronchitis
Acute bronchitis is an infection of the bronchial tree, or the main air passages to the lungs. When these air passages become infected, they swell and fill with mucus, making it difficult to breathe. Acute bronchitis generally follows a viral respiratory infection. It is spread from person to person by coughing. You can “catch” acute bronchitis by breathing in the viruses or touching hands coated with the viruses. Symptoms include:

  • Tickle deep in the throat, which develops into a dry cough
  • Cough may become productive with thick yellow mucus
  • Slight fever
  • Fatigue
  • Shortness of breath
  • Chest pain