Most doctors make a diagnosis of influenza based on symptoms, but some occasionally perform influenza testing. If a person is displaying symptoms of influenza and the flu is going around in the person's local area, a doctor may diagnose his patient based on that information and begin treating her with flu medicine. A definitive diagnosis of influenza can be determined with a test for influenza. There are a few different types of influenza tests, including culture tests and rapid antigen tests. All of these tests are typically reliable, although the simplest of the tests does not always indicate what type of influenza a person may have.
The symptoms of influenza and how they began are often a very good indicator of whether influenza is present. It can be hard to tell the difference between influenza and the common cold because the symptoms are somewhat similar, but when a person has a cold, he usually gets sick gradually. Influenza tends to come on suddenly, with little to no warning beforehand. People additionally tend to get much sicker with influenza than they do with the common cold, and they might experience severe body aches along with headaches, which is usually rare with a cold. A person with influenza might also feel much more lethargic and weak than someone who only has a cold.
A diagnosis of influenza can often be made with a simple test kit a doctor can use in her office. This simple test is typically performed by taking a sample of mucus from the patient's nose and mixing it with a solution inside a test tube. After a short period of time, the solution will display a colored line or lines if influenza is present in a person's body. While this test is effective, it is not always able to determine what type of influenza a person has. For more specific results, a doctor may want to base her diagnosis of influenza on other types of tests.
Culture tests tend to be very useful for diagnosing influenza. To perform a culture test, doctors typically get a specimen from their patients and watch the specimen for a period of two to ten days. During this time, an infection will grow on the specimen if a person has influenza. The primary downside to this type of test is that, by the time the results are available, the patient has probably already suffered through the worst of influenza if he did have it. A rapid antigen test also requires a sample specimen and can produce results much faster, typically within 30 minutes or less.
A person who is concerned that he may have influenza should get to the doctor quickly so that a diagnosis of influenza can be made. If influenza is diagnosed, a doctor can prescribe antiviral medicine that may shorten the duration of the flu and make a person feel much better. Treating influenza with antiviral flu medicine can be helpful, but the medicine may be ineffective if a person doesn't get the prescription within the first few days of the onset of influenza.
