How can you tell if your symptoms are from a bacteria, a virus, or allergies? It’s tricky. Doctors struggle with this often. In fact, I had an intern recently who thought an 11-year-old had an ear infection, but it was really an asthma attack. Even with training it is still difficult. However, there are a few simple things that can help distinguish between the three. These aren’t perfect rules, but they do help.
One of the first things to ask is how long the symptoms have been present. If the answer is for months or weeks, it is almost always an allergy. Viruses usually begin to improve after three days, even though sometimes symptoms last for several days longer. Bacterial infections usually progress at about the same rate but tend to get worse until treated. It is possible to get back-to-back viral infections, especially at the start of the school year. It is also possible for a viral illness to progress to a bacterial illness.
Another helpful question is where the symptoms are located. Allergies almost always affect both sides of the body. Bacterial infections are mostly one sided. A bacterial sinus infection is often just one side. Bacterial eye infection is typically just one eye, at least to start with. Ear infections are almost always one sided and very often bacterial. Viruses often involve both sides. Viruses can also cause a wide range of symptoms. If you have symptoms that also involve your stomach, skin and upper respiratory system, it is almost certainly a virus.
Sometimes trying a specific treatment can lead to knowing what is wrong. If an allergy pill helps, then it almost certainly is an allergy. If Tylenol or Motrin help, it is more likely an infection. An inhaler will help with wheezing and cough from allergies. Sometimes an inhaler can help with a viral respiratory infection. It usually doesn’t help with a bacterial respiratory infection. A high dose of Vitamin C, 1000-2000 mg might help with an infection, but is unlikely to help with allergies.
If you have a fever, it is not allergies. A true fever is over 38 degrees Celsius or 100.4 degrees Fahrenheit. If you have a fever, it will likely take an exam and some tests to help differentiate between a virus and a bacterial infection. It is difficult to test for every virus as there are hundreds of different viruses that can infect humans, and most viruses cause similar symptoms. Bacterial infections are typically easier to pin down.
Allergies and infections are common. It is hard to know which is causing the problem. However, it is important to know because all three are treated differently. That is why we have professionals. But hopefully, these tips can help. For any questions or uncertainty consult your healthcare provider.
– Dr. Daniel Sterner, DO is a provider at Health West American Falls. He specializes in family medicine and obstetrical care and is accepting new patients.
