Diagnosis of Viral Upper Respiratory Infections (Colds and Influenza)
Based on your symptoms and a physical exam, your doctor can diagnose a cold or influenza. In some situations, tests, such as throat culture or blood count, may be ordered to characterize the severity of the condition and identify other related problems.
Identification of the specific virus causing your symptoms is not usually necessary because it usually does not make a difference in treatment. However, if influenza A virus is suspected, on the basis of the time of year and community public health reports, high-risk patients may be treated specifically for that virus.
Diagnosis may include the following:
—Taking your temperature every 6-8 hours can help define the severity of your illness.
—This is a routine check for conditions such as diabetes that may make your acute case of cold or influenza worse.
This is not usually done for colds or flu unless there is another reason to suspect urinary infection, such as suggestive symptoms or a fever with few other symptoms.
—This is another routine test to assess your general health and your ability to fight off the illness.
It is not done routinely in colds or flu, but only if necessary such as if a person is very sick.
—This is done if there are signs or symptoms of sore throat in order to rule out strep throat.
—If your physician suspects that your upper respiratory infection has spread to your lungs, an x-ray may be done to check for pneumonia.
Beers MH, Berkow R.
The Merck Manual of Diagnosis and Therapy
. 17th ed. Hoboken, NJ: John Wiley and Sons; 1999.
Fauci AS, Braunwald E, et al.
Harrison's Principles of Internal Medicine
. 14th ed. New York, NY: The McGraw-Hill Companies; 2000.