It can be difficult to tell the difference between a virus or bacterial infection because they may both cause the same sorts of symptoms. Many people think symptoms such as fever and yellow or greenish mucus mean a person has a bacterial infection, but these symptoms can occur with viruses as well. A person who is suffering from a very high fever may be more likely to have a bacterial infection. Likewise, an infection that lasts longer than about 10 to 14 days or worsens after a few days may be bacterial. To be sure, however, you will most likely need to visit a medical professional for tests that can determine the cause of an infection.
Without the help of a medical professional, it can be difficult to determine whether you have a virus or bacterial infection. Unfortunately, you can have the same symptoms with with either: both are capable of causing fevers, sore throat, fatigue, and aches and pains. You may have discolored mucus, headaches, upset stomach and a range of other symptoms. You can, however, consider the extent of your symptoms and how long they last in judging what sort of infection you have.
One factor to consider is the severity of the fever. Often, individuals with viruses have low-grade fevers while those with bacterial infections have higher temperatures. It is possible to develop a high fever with a virus, however, and vice versa. You might also suspect that you have a bacterial infection rather than a virus if the high fever persists for more than a couple of days.
Sometimes, you can judge whether you have a virus or bacterial infection by changes in your symptoms. For example, if your symptoms grow worse after a few days of being ill, you may have a bacterial infection. This could mean that you started out with a virus that has become complicated by bacteria or that you had a bacterial infection all along. Additionally, symptoms that are initially severe and do not improve may point to a bacterial infection.
The duration of your illness may also provide clues. Generally, you can expect many, though not all, viral infections to resolve within about 10 to 14 days. If you are ill for longer than two weeks, you might have a bacterial infection instead.
The best way to learn whether you have a virus or a bacterial infection is to have a medical professional examine you. He or she can run tests to determine the cause of your illness, often using throat or urine cultures or blood tests for this purpose.